C5 K2 Finds

• by Martti_Holst_Kristiansen

  The K2 C5 lightcurves are now online, thanks to Al Schmitt (HEK) for providing us with the long cadence PDCSAP_FLUX lightcurves for LcViewer.

  ---

  Planet Candidates (Transits):

  211309989 EB maybe additional transit at 2360.87 BKJD

  211311380 Multi (T1 = 2309.00 BKJD), (T2 = 2319.27 BKJD), (T3 = 2353.94 BKJD) could be more or cont.

  211319617 (P = 8.873) could be EB cont.

  211351097 (T = 2328.83 BKJD)

  211351816 (P = 8.402)

  211359660 (P = 4.736)

  211390677 (T = 2318.75 BKJD)

  211391664 (P = 10.129)

  211399359 (P = 3.115) Could be cont.

  211413752 (P = 9.327)

  211418290 (P = 5.034) Could be showing signs of moon signals or starspots

  211418729 (P = 11.356)

  211420635 (T = 2339.44 BKJD)

  211424769 (P = 5.177)

  211432103 (P = 0.93)

  211432167 (P = 5.813)

  211442297

  211490999 (P = 9.842)

  211503363 (T = 2364.50 BKJD)

  211509553 perhaps cont./EB

  211525389 (P = 8.263)

  211536223 EB maybe additional transit at ~2342.49 BKJD

  211543770 Could be two signals

  ---

  Eclipsing Binary Candidates:

  211309989 maybe additional transit at 2360.87 BKJD

  211310837

  211312968

  211324599

  211330130

  211338746

  211339469*

  211342524

  211345799

  211350898

  211361880

  211371463

  211380136

  211385544

  211389268

  211391083

  211391190

  211394059

  211394147

  211396167

  211405917

  211408138

  211409299

  211409713

  211410762

  211412192

  211413463

  211413815

  211416577

  211421547

  211430148

  211431013

  211432905

  211432946

  211434817

  211462458

  211464017

  211479262

  211480475

  211481740

  211484776

  211489039

  211489484

  211489847

  211490542

  211493634

  211497712

  211498244

  211499872

  211504561

  211505107

  211509975

  211516905

  211517741

  211518347

  211519965

  211523408

  211524558

  211526186

  211526536

  211529914

  211536223 Maybe additional transit at ~2342.49 BKJD

  211538336

  211538914

  211549874

  211563123

  211564796

  211567126

  211569350

  211569573

  211573254

  ---

  GDOR:

  211318888

  211323059

  211334044

  211351999

  211389052

  211391869

  211395085

  211402632*

  211405240

  211421716

  211424858*

  211478023

  211488803

  211488900

  211507624

  211537751

  211556780

  ---

  RR Lyrae types:

  211307207

  211327055

  211348419

  211398225

  211398788

  211410664

  211412103

  211484212

  211492294

  211496026

  211503714

  211523969

  211532246

  211553019

  211565461

  ---

  CV

  211545679

  ---

  Other

  211321066

  211400757

  211511906

  211545362

  Posted November 3, 2015 12:31 PM

• by Shellface

  Ah, jeez, already… I definitely don't have enough time in my life.

  This campaign will be very astrophysically important. It contains much of the constellation of Cancer (though unfortunately not 55 Cancri), in particular two of the most important open clusters in the sky, M67 and M44 (Praesepe). Though these two are less well-known than the Pleiades and Hyades observed in the previous campaign, they are still of huge value.

  M67 is unusually old for an open cluster, with an age of roughly 4 Gyr. Its stars have chemistries very similar to the Sun, which had raised suggestions that the cluster may have been the solar birthplace; however, a recent work (Pichardo et al. (2012)) has largely dismissed that possibility. Still, the cluster is an extremely important target, and K2 observations ought to be highly worthwhile. Planet detections here will be valuable; It's worth noting that the cluster already has 3 known planets, of which 2 are Hot Jupiters.

  Praesepe is generally believed to be related to the Hyades, as they have reasonably coincident space motions and comparable ages. It is still very important, but perhaps not as much as its relative. Planet detections will be similarly valuable here, and again it is worth noting that the cluster has 2 known hot jupiters already.

  The rest of the field is fairly ordinary; it lies reasonably far from the galactic plane, so reddening will not be too strong.

  This is undoubtedly one of the most important K2 fields, and I wish everyone luck with discoveries. While I go and not have spare time.

  Posted November 3, 2015 7:33 PM

• by JKD

  211309989 - agree, obviously an EB with a 3rd object around.

  Eclipsing Binary: p~7.533 days with an obvious TTV

  Third object:

  Signal at 2360.88 BKJD

  Transit Time 8.33 hrs

  Signal Depth 18612 ppm

  Posted November 3, 2015 7:48 PM

• by JKD

  211308771 - PC

  Signal at 2330.046 BKJD

  Transit Duration 2.94 Hrs

  Signal Depth 3881 ppm

  Posted November 3, 2015 8:06 PM

• by JKD

  211311380 - likely contaminated by an EB

  EB with signals at

  s1 2309.011 BKJD

  s2 2353.899 BKJD

  Posted November 3, 2015 8:32 PM

• by zoo3hans

  Ok, let's try to contribute (as always I'm starting from the end and work towards Martti):

  Planet Candidates (Transits) including additional candidates from the C5_K2_Korr light curves (by courtesy of Andrew Vanderburg, and Al Schmitt with his excellent LcViewer) :

  EPIC 211305568 might have two transits at 2359.44 , 2324.8 , possible period P1=34.64 days, depth about 0.002, duration about 4.5 hours. Hm, but in the Everest V2 LC it looks like the transit at 2324.8 is actually a double transit, and one period of this MPC is P2=11.546 days, starting at BKJD 2313.24. Another (different) transit at BKJD 2367.9. Also P3=18.4498 days, starting at BKJD 2324.775, duration 4.4 hours, depth 0.0024, P4=0.3956 days, starting at BKJD 2307.749, duration 1.4 hours, depth 0.0008.

  (EPIC 211307956 Probably bad glitch at BKJD 2343.5, also for EPIC 211230123)

  (Martti: 211309989 EB maybe additional transit at 2360.87 BKJD)

  EPIC 211311054 Very fast occuring dips, period about 0.145 days, depth only 0.0009. I assume contamination by a BGEB.

  (Martti: 211311380 Multi (T1 = 2309.00 BKJD), (T2 = 2319.27 BKJD), (T3 = 2353.94 BKJD) could be more or cont.)

  (Martti: 211319617 P = 8.873, EPIC 211319617, regular transits with period 8.868 days, U-shaped, no secondaries visible, to me it looks like a valid candidate)

  EPIC 211315224 Maybe single transit at BKJD 2342.8 , depth 0.0023, duration 11 hours.

  EPIC 211320412 Maybe single transit at BKJD 2352.7 , depth 0.0002, duration 12 hours.

  EPIC 211328748 4 transits at BKJD 2324.13, 2341.29, 2358.47, 2375.65. Period about 17.17 days. Depth 0.00026. Duration about 4 hours.

  EPIC 211331236 Multiplanet candidate. One period 1.292 days. Starting at BKJD 2309.7037. Depth about 0.0015. Duration about 2 hours. Another object seems to have a period around 5.45 days. Similar depth. Duration about 3 hours. Starting at BKJD 2310.5137. Now confirmed both planets in https://arxiv.org/pdf/1710.03239.pdf

  EPIC 211335477 Maybe single transit at BKJD 2358.75, depth 0.0002, duration about 11 hours..

  EPIC 211336073 Maybe transit at BKJD 2332.46 , depth 0.006, duration 5.5 hours.

  EPIC 211340040 Maybe transit at BKJD 2338.18 , depth 0.001, duration 8 hours.

  EPIC 211346584 Maybe transit at BKJD 2353.67 , depth 0.016, duration 4.5 hours.

  EPIC 211347012 Maybe grazing long transit at BKJD 2342.68 , depth 0.0027, duration 8.5 hours.

  (Martti: 211351097 (T = 2328.83 BKJD))

  EPIC 211351543 Maybe single transit at BKJD 2373.79 , depth 0.00044, duration about 5 hours.

  (Martti: 211351816 (P = 8.402)) EPIC 211351816 first transit at 2309.06, period 8.402 days, depth 0.0009, duration about 7 hours. There seem to be other transits present in the LC as well.)

  EPIC 211355342 Period 6.893 days, starting at BKJD 2310.8 , depth 0.0008, duration about 3 hours, fairly U-shaped.

  EPIC 211356358 Maybe transit at BKJD 2352.7 , depth 0.005, duration 6.5 hours.

  (Martti: 211359660 (P = 4.736)) EPIC 211359660 P = 4.736 days, depth 0.0012, duration about 3.5-4.0 hours.)

  EPIC 211376702 Maybe transit at BKJD 2331.1 , depth 0.002, duration about 16.5 hours.

  (Martti: 211390677 (T = 2318.75 BKJD)) Very strange dip at 2318.8. Maybe a large ringed Jupiter-like planet? Depth 0.01, "ring"-depth 0.005. BUT according to Andrew Vanderburg it's a software issue (mentioned by ajamyajax in a private email).)

  (Martti: 211391664 (P = 10.129)) Period about 10.138 days, depth 0.001, duration about 5.5 hours. Substructure visible in the transits, probably star spots -> maybe rotation period of star can be found.)

  EPIC 211392382 Maybe transit at BKJD 2343.52 , depth about 0.007, duration about 27.5 hours.

  (Martti: 211399359 (P = 3.115) Could be cont.) EPIC 211399359 P = 3.115 days, depth 0.027, duration about 3 hours. Maybe Hot Jupiter.)

  EPIC 211401787 Period 13.77 days, starting at BKJD 2318.06 , depth 0.0003, duration about 3.5 hours.

  EPIC 211406700 Maybe transit at BKJD 2342.75 , depth 0.0009, duration about 14.5 hours.

  EPIC 211407755 Period about 36.08 days, at BKJD 2327.24 and 2363.32 , depth 0.004, duration about 3.5 hours.

  EPIC 211411112 Single transit at 2345.95 , depth 0.026, duration about 4.5 hours, rather V-shaped.

  EPIC 211413463 As Martti mentioned probably EB, but still a slight change for a grazing HJ, depth 0.03, duration 3.5 hours, period around 3.25175 days.

  (Martti: 211413752 (P = 9.327)) Period around 9.324 days, starting at 2307.84, depth 0.0006, duration about 4 hours.

  EPIC 211416496 Maybe transit at 2342.69 , depth 0.002, duration about 8 hours.

  (Martti: 211418290 (P = 5.034) Could be showing signs of moon signals or starspots)

  (Martti: 211418729 (P = 11.356)) EPIC 211418729 Period about 11.39 days, depth 0.0154, duration about 4.5 hours, U-shaped, looks like a fine warm Jupiter.

  (Martti: 211420635 (T = 2339.44 BKJD))

  (Martti: 211424769 (P = 5.177))

  (Martti: 211432103 (P = 0.93))

  (Martti: 211432167 (P = 5.813)) EPIC 211432167 Period around 5.8177 days, starting at BKJD 2308.93, depth 0.0111, duration about 4.5 hours.)

  (Martti: 211442297) P=20.27 days, depth 0.017, U-shaped, probably a good planet candidate. Also mentioned by ajamyajax and JKD.

  EPIC 211468623 Maybe transit at BKJD 2352.35 , depth 0.0012, duration about 8.5 hours.

  (Martti: 211490999 (P = 9.842)) P=9.844 days, see also comment by ajamyajax http://talk.planethunters.org/?_ga=1.110727493.1777704650.1398881647#/boards/BPH0000007/discussions/DPH00019on?page=6 )

  EPIC 211491044 Maybe transit at 2310.98 and 2360.86 , depth 0.0004, duration about 6.5 hours, possible period around 49.88 days.

  EPIC 211496372 Maybe transit at BKJD 2335.75, depth 0.0009, duration about 12.5 hours.

  EPIC 211496731 Maybe transit at 2317.82 and 2362.85 , depth 0.0024, duration about 6.5 hours, possible period around 45.03 days.

  (Martti: 211503363 (T = 2364.50 BKJD)) EPIC 211503363 Obvious transit at BKJD 2364.52, depth 0.0039, duration about 0.93 days, nicely U-shaped. So this seems to be a good long period planet candidate.)

  EPIC 211503470 Maybe transit at BKJD 2353.13, depth 0.0003, duration about 3.5 hours, but probably contamination.

  EPIC 211505089 Period about 24.46 days, starting at BKJD 2313.93, depth 0.0007, duration about 6 hours.

  (Martti: 211509553 perhaps cont./EB) EPIC 211509553 P=20.365 days, depth 0.036, U-shaped, a bit on the deep side, but might still be a valid PC (I see no secondaries).)

  EPIC 211518462 Maybe transit at BKJD 2352.4, depth 0.0002, duration 6.5 hours.

  (Martti: 211525389 (P = 8.263)) EPIC 211525389 Period around 8.266 days, starting at BKJD 2315.0, depth 0.0014, duration 4 hours.)

  EPIC 211529065 Period about 4.4 days, starting at BKJD 2309.97, depth 0.0013, duration about 3 hours.

  (Martti: 211536223 EB maybe additional transit at ~2342.49 BKJD)

  (Martti: 211543770 Could be two signals)

  EPIC 211562654 Multiplanet system. One period about 10.794 days, starting at BKJD 2314.78, depth 0.0006, duration about 4 hours. The second planet has period 22.63 days, starting at BKJD 2311.14, depth 0.0009, duration about 5 hours. There is even a chance for a small third planet with period 4.249 days, especially visible around BKJD 2346.56 and 2350.78, depth 0.0005, duration about 3 hours.

  EPIC 211578235 Period about 11.007 days, starting at BKJD 2314.98, depth 0.0058, duration 2.5-3 hours.

  EPIC 211579112 P=17.705 days, starting at BKJD 2323.42, depth 0.008, duration about 3 hours.

  EPIC 211579683 Period about 9.015 days, starting at BKJD 2311.6, depth 0.0008, duration about 4 hours.

  EPIC 211594205 Period about 16.99 days, starting at BKJD 2315.5, depth 0.00035, duration about 3 hours, U-shaped.

  EPIC 211598816 Single transit at BKJD 2363.35, depth 0.0097, duration about 3.5 hours.

  EPIC 211606790 P=37.24 days, depth 0.007, starting at BKJD 2317.08

  EPIC 211611158 Period about 52.71 days, starting at BKJD 2326.17, depth 0.0007, duration about 5.5 hours.

  EPIC 211623903 P=0.808 days, depth 0.025, starting at BKJD 2306.86

  EPIC 211633458 Single long transit at BKJD 2368.78, depth 0.001, duration about 11 hours, U-shaped.

  EPIC 211643038 Single transit or glitch at BKJD 2343.4, depth 0.004, duration about 0.9 days.

  EPIC 211680698 Period 50.92 days, starting at BKJD 2327.49, depth 0.0012, duration about 5 hours, U-shaped.

  EPIC 211682544 P=50.82 days, depth 0.0007, duration about 3.5 hours, transit at BKJD 2312.57 and 2363.39

  EPIC 211685045 P=0.769 days, depth 0.025, starting at BKJD 2306.85

  EPIC 211713099 P=8.56286 days, depth 0.0055, starting at 2308.15 , maybe TTV's present

  EPIC 211719362 P=0.20114 days, depth 0.004, duration about 5 hours, starting at 2306.876

  EPIC 211719484 P=0.361 days, depth 0.006, starting at BKJD 2306.99

  EPIC 211731027 Maybe single transit at BKJD 2309.35, depth 0.01, duration 5.5 hours.

  EPIC 211732823 Maybe long transit at BKJD 2311.3, depth 0.0007, duration 18 hours, another short one at BKJD 2365.2, depth 0.0007, duration about 2.5 hours.

  EPIC 211733267 P=8.658 days, depth 0.007, duration about 2.5 hours, starting at BKJD 2311.93

  EPIC 211736671 P=4.7334 days, depth 0.0008, starting at BKJD 2307.4, probably TTV's present

  EPIC 211743521 Maybe single transit at BKJD 2342.66, depth 0.0006, duration about 5.5 hours.

  EPIC 211754321 maybe single transit at BKJD 2330.25

  EPIC 211755473 Maybe period 26.24 days, starting at BKJD 2326.85, depth 0.0018, duration about 3.5 hours.

  EPIC 211763214 P=21.19 days, depth 0.00035, starting at BKJD 2313.6 (ajamyajax pointed out the real period)

  EPIC 211765775 Period about 43.12 days, starting at BKJD 2329.42, depth 0.0006, duration about 7.5 hours. Other dips seem to be present as well.

  EPIC 211770696 P=16.273 days, depth 0.0008, starting at BKJD 2312.98

  EPIC 211770795 Maybe multiplanet system, one planet with period 7.726 days, depth 0.0015, duration about 4 hours, starting at BKJD 2308.1, another planet maybe at BKJD 2316.2.

  EPIC 211770867 P=27.694 days, depth 0.021, starting at BKJD 2314.89 , U-shaped, maybe fine Warm Jupiter, maybe small secondary transits starting at BKJD 2325.95

  EPIC 211775796 Maybe single transit at BKJD 2352.99, depth 0.001, duration 6.5 hours.

  EPIC 211791178 Period about 9.563 days, starting at BKJD 2313.91, depth 0.0008, duration about 3.5 hours.

  EPIC 211798340 Period 44.99 days, starting at BKJD 2311.06, depth 0.0002, duration about 7 hours.

  EPIC 211799258 Period 19.534 days, starting at BKJD 2320.13, depth 0.0652, duration only about 2 hours. Additional dips at BKJD 2340.65, 2342.56.

  EPIC 211800191 P=1.1062 days, depth 0.001, starting at BKJD 2306.65

  EPIC 211804579 Period 1.5233 days, starting at 2308.2, depth 0.0005, duration about 4 hours.

  EPIC 211808055 P=3.3814 days, depth 0.0017, starting at BKJD 2309.62 Probably contamination by EPIC 211807843 (noted by ajamyajax )

  EPIC 211807843 EB, but additional dip at BKJD 2341.77, depth 0.002, duration 6 hours, "flanks" at BKJD 2343.4, another transit event?

  EPIC 211816003 P=14.45 days, depth 0.0012, starting at BKJD 2311.86

  EPIC 211817229 Period about 2.177 days, starting at BKJD 2307.69, depth 0.004, duration about 2 hours.

  EPIC 211817572 P=2.2595 days, depth 0.005, starting at BKJD 2307.02

  EPIC 211818569 P=5.1854 days, depth 0.013, starting at BKJD 2310.56

  EPIC 211821192 maybe single transit at BKJD 2344.2, depth 0.001, duration 0.24 days, U-shaped

  EPIC 211822797 Period about 21.17 days, starting at BKJD 2311.41, depth 0.0015, duration about 4.5 hours.

  EPIC 211825799 Period about 33.293 days, starting at BKJD 2328.21, depth 0.0008, duration about 12.2 hours.

  EPIC 211827189 Maybe single transit at BKJD 2337.82, depth 0.0009, duration 6-7 hours..

  EPIC 211833449 P=0.2673 days, depth 0.03, starting at 2306.86

  EPIC 211842983 maybe single transit at BKJD 2322.3, depth 0.0005

  EPIC 211846823 P=40.12 days, depth 0.0003, starting at BKJD 2312.95 (although this might be a glitch, I've seen this feature on other stars as well, for example 211829827)

  EPIC 211886472 P=19.64 days, depth 0.0057, starting at BKJD 2319.38

  EPIC 211892898 single long transit at BKJD 2356.4, depth 0.0075, duration about 2.5 days, U-shaped

  EPIC 211893543 Maybe period 29.25 days, starting at BKJD 2329.9, depth 0.0004, duration about 4.5 hours. Other dips as well.

  EPIC 211897901 Single transit at BKJD 2348.63, depth 0.0011, duration about 6 hours.

  EPIC 211906650, P=41.44 days, depth 0.001, starting at BKJD 2321.85

  EPIC 211916756 P=10.135 days, depth 0.008, starting at BKJD 2307.74

  EPIC 211919004 P=11.7195, depth 0.0012, starting at BKJD 2316.09

  EPIC 211921217 Maybe single transit at BKJD 2352.97, depth 0.002, duration about 8.5 hours.

  EPIC 211923431 Period about 29.74 days, starting at BKJD 2310.82, depth 0.0008, duration 6 hours.

  EPIC 211924561 single transit at 2346.9, depth 0.0021, a bit V-shaped though.

  EPIC 211924657 P=2.645 days, depth 0.0045, starting at BKJD 2309.001, TTY's present. Now confirmed in https://arxiv.org/pdf/1710.03239.pdf

  EPIC 211929937 P=3.4765 days, depth 0.021, starting at BKJD 2309.45, this looks like a fine Hot Jupiter

  EPIC 211938121 Maybe single transit at BKJD 2323.24, depth 0.0045, duration 8.5 hours.

  EPIC 211939692 Clearly a multiplanet system. Inredible system, if real: BKJD 2333.05 (depth 0.0005, 8.5h) , BKJD 2337.5 (depth 0.001, 10.5h) , BKJD 2341.0 (depth 0.00055, 8.5h) , BKJD 2358.9 (depth 0.0007, 13h) , BKJD 2359.9 (depth 0.00055, 8.5h) , 2380.5 (depth 0.00055, 8.5h).

  EPIC 211941362 Maybe single transit at BKJD 2353.16, depth 0.0025, duration 4.5 hours, but probably contamination.

  EPIC 211945201 P=19.49 days, depth 0.0015, starting at BKJD 2325.83, now confirmed in https://arxiv.org/pdf/1805.03466.pdf

  EPIC 211953574 Maybe single transit at BKJD 2360.59, depth 0.0005, duration 5.5 hours.

  EPIC 211970234 P=1.4833 days, depth 0.015, starting at BKJD 2307.4 , the LC is not well defined (weak star?)

  EPIC 211972200 P=3.1545 days (if HJ) or 6.309 days (if EB), depth 0.017

  EPIC 211978909 P=8.935 days, depth 0.0016, starting at BKJD 2307.86 , probably contamination by BGEB from looking at the LC

  EPIC 211978988 P=36.55 days, depth 0.0009, starting at BKJD 2319.73

  EPIC 211979325 P=1.0385 days, depth 0.022, starting at BKJD 2306.97, maybe HJ oder WD

  EPIC 211980360 Period 5.388 days, starting at BKJD 2308.75, depth 0.025, duration 4.5 hours. Period could also be half this value, i.e. 2.694 days, or else contamination by a BGEB.

  EPIC 211987231 P=17.035 days, depth 0.023, starting at BKJD 2308.81, maybe a Warm Jupiter, although a bit V-shaped

  EPIC 211988320 Multiplanet system, one period 63.85 days, starting at BKJD 2309.71, depth 0.002, duration 6 hours. Second period maybe 36.43 days, starting at BKJD 2329.2, depth 0.0015, duration 5 hours.

  EPIC 211990866 P=1.674 days, depth 0.0006, starting at BKJD 2307.71

  EPIC 211991644 Maybe single transit at BKJD 2331.1, depth 0.0007, duration 13 hours.

  EPIC 211993818 P=8.9865 days, depth 0.02, starting at BKJD 2307.04, could be a Hot Jupiter (I see no secondary transits), maybe another small planet at BKJD 2339.53 and 2375.93 with a possible period of 36.4 days, depth 0.0006

  EPIC 212006318 Maybe single transit at BKJD 2351.4, depth 0.0003, duration 6.5 hours, other transits with period 14.46 days, starting at BKJD 2314.3, depth 0.0002, duration about 6 hours.

  EPIC 212006344 Period 2.22 days, starting at BKJD 2308.82, depth 0.0004, duration about 2 hours. Now confirmed in https://arxiv.org/pdf/1710.03239.pdf

  EPIC 212008766 P=14.13 days, depth 0.0017, starting at BKJD 2312.12

  EPIC 212009016 Maybe period 37.28 days, starting at BKJD 2331.68, depth 0.0006, duration about 4.5 hours.

  EPIC 212011230 single transit at BKJD 2332.48, depth 0.0053, U-shaped

  EPIC 212012119 Varoius dips, depth about 0.001, duration about 3 hours, one period 3.281 days, starting at BKJD 2309.138, depth 0.0013, duration 2.5 hours.

  EPIC 212026444 Maybe single transit at BKJD 2343.4 , depth 0.0007, duration 21 hours.

  EPIC 212030008 Maybe single transit at BKJD 2338.98, depth 0.003, duration about 8 hours.

  EPIC 212066407 P=0.822 days, depth 0.0005, starting at BKJD 2307.367

  EPIC 212069706 P=0.13695 days, depth 0.002, starting at BKJD 2306.65

  EPIC 212069861 Period 30.96 days, starting at BKJD 2314.49 , depth 0.002, duration about 4 hours. Now confirmed in https://arxiv.org/pdf/1710.03239.pdf

  EPIC 212085656 Maybe period 50.63 days, starting at BKJD 2319.5, depth 0.03, duration only 2.5 hours, so this could be contamination though.

  EPIC 212091090 Maybe single transit at BKJD 2342.73 , depth 0.0007, duration 12.5 hours, rather V-shaped though. Maybe a smaller one at BKJD 2326.12 , depth 0.0003, duration about 8.5 hours.

  EPIC 212092964 maybe P=58.8 days, at 2319.2 and 2378.0, although not really sure about this one

  EPIC 212098979 Maybe transit at BKJD 2344.48, depth 0.0006, duration about 5.5 hours.

  EPIC 212099230 P=7.113 days, depth 0.0007, starting at BKJD 2308.96

  EPIC 212110888 P=2.995 days, depth 0.0075, starting at BKJD 2308.35 , it looks like a fine Hot Jupiter. Now confirmed in http://arxiv.org/abs/1601.07635 and http://arxiv.org/abs/1602.00638 and http://arxiv.org/abs/1603.01721

  EPIC 212130773 Period 18.715 days, starting at BKJD 2318.91, depth 0.002, duration about 7 hours.

  EPIC 212132195 P=26.2 days, depth 0.001, starting at BKJD 2331.4

  EPIC 212138198 P=3.208 days, depth 0.002, starting at BKJD 2309.34

  EPIC 212146642 Maybe single transits at BKJD 2342.73 , depth 0.0008, duration about 12 hours, at 2359.45, depth 0.003, duration about 3 hours.

  EPIC 212148549 Maybe single transits at BKJD 2312.31 , depth 0.0004, duration 6.5 hours.

  EPIC 212150006 P=0.8983 days, depth 0.0025, starting at BKJD 2306.98

  EPIC 212152341 Period 6.677 days, starting at BKJD 2308.3 , depth 0.06, duration about 2.5 hours. Maybe it's an EB instead since the depth is rather large.

  EPIC 212154564 P=6.415 days, depth 0.007, starting at BKJD 2309.165

  EPIC 212157262 Multiplanet system. One period 7.1502 days, starting at BKJD 2313.32 , depth 0.0009, duration about 3.5 hours. Second period 13.606 days, starting at BKJD 2308.46, depth 0.0007 duration about 5 hours.

  EPIC 212164470 P=7.81 days, depth 0.0007, starting at BKJD 2311.87

  EPIC 212165050 P=16.825 days, depth 0.0055, starting at BKJD 2313.3

  Eclipsing Binary Candidates:

  211563123

  211564796 nice eccentric EB

  211567126

  211569350

  211569573

  211573482

  211578677

  211581700

  211586814

  211604396

  211604668

  211613886

  211617231 nice eccentric giant EB

  211619120

  211626833

  211631904

  211681365

  211682657

  211685048

  211693443

  211703878

  211726283

  211728689

  211730838

  211732798

  211732801

  211744153 maybe contamination since the depth is only 0.007 for the primary eclipse

  211759736 giant EB, eclipses at BKJD 2317 2335.3, 2353.5, 2371.8, period about 36.5 days. Maybe even a circumbinary planet with transits at 2310.25, 2332.8, 2333.8, 2373.3, 2374.3, depth 0.0015, duration about 5.5 hours.

  211770390

  211770578 nice slightly eccentric detached EB

  211772227 P=34.9 days, eccentric, depth 0.009 (secondary 0.006)

  211781105

  211782603

  211785805

  211785852

  211790891

  211796803

  211797674

  211804514

  211805860

  211807843

  211812160

  211814733 Probably EB (not PC), V-shaped, secondaries visible, period 14.71 days, depth 0.0055, starting at BKJD 2312.89

  211820126

  211822953

  211825356

  211828658

  211831378

  211833616

  211834405

  211839430

  211839462 (probably contaminated by 211839430)

  211848129

  211885185 nice detached EB

  211894612 single eclipse at BKJD 2349.92, depth 0.045

  211895405

  211902535 Eccentric EB

  211910237

  211910968 P=4.5456 days, depth 0.016, starting at BKJD 2306.94, however I think it's an EB because every second dip occurs a bit earlier than the others

  211914718 probably EB

  211915147

  211918335 probably EB

  211918830

  211918985 (probably contamination by 211920612)

  211919528 (probably contamination by 211920612)

  211919680 (probably contamination by 211920612)

  211920604 (probably contamination by 211920612)

  211920612 very nice semi-detached EB

  211927125 probably a triple system with an unseen third star

  211929618

  211931604

  211936444

  211942157

  211944670 (maybe the same as 211944676 and 211944856)

  211944676 (maybe the same as 211944670 and 211944856)

  211944856 (maybe the same as 211944670 and 211944676)

  211945144

  211946007

  211948599

  211953866

  211958340

  211962644

  211972086

  211972744 nice eccentric detached EB, P=45.904 days

  211972837 very nice semi-detached EB, down to below 0.2

  211973404 short period but large delta_mag, so probably EB instead of pulsating variable

  211978865

  211980250 very nice EB, the secondary eclipse has a distinct subfeature

  211980366

  211981609

  211982518

  211982753

  211988016

  211995398 P=32.55 days, depth 0.055, maybe BD

  211995462 long period EB, secondary eclipse at 2306.75, primary eclipse at 2370.28

  211995966

  211996855

  211997641 P=3.489 days

  211999656

  212000980

  212002525

  212008305

  212009702 nice semi-detached EB

  212010289 nice deep eclipses

  212011476

  212012030 long period EB, eclipse at BKJD 2341.47

  212012387 P=6.489 days

  212018340

  212019055 Nice semi-detached EB

  212019712

  212020442 P=3.894 days, depth 0.05, starting at BKJD 2306.88, slightly eccentric, maybe BD

  212024647

  212029934

  212037403 P=3.40857 days

  212037558

  212068987

  212082682 P=3.7975 days

  212083250

  212085740 P=4.8453 days

  212096658 Nice detached EB

  212098045

  212109135 nice eccentric detached EB

  212110007 nice detached EB with small secondary eclipses, P=16.71 days

  212111327

  212116340

  212120135

  212122623

  212137314 P=3.21 days

  212137767

  212145065

  212147322

  212148673

  212152316 very nice eclipse at BKJD 2374.2 , maybe ring system about the companion star

  212152922

  212155299

  212158225 Period about 0.1332 days, depth 0.0005, duration about 1.5 hours. It coiuld also be a very short period PC.

  212159519

  212159987

  212163353

  212164476

  212171851 nice

  212172212

  212173112 very nice EB

  212175535 maybe EB

  GDOR/DSCT:

  211573671 (G)

  211699931 (D)

  211717807 (D)

  211735933 (D)

  211765471 (D)

  211807052 (D)

  211823930 (D)

  211828464 (D)

  211886104 (D)

  211898878 (D)

  211911224 (G)

  211914004 (D)

  211914580 (D)

  211916195 (D)

  211931309 (D)

  211935741 (D)

  211936163 (D)

  211957791 (D)

  211973314 (G)

  212008515 (D)

  212031760 (D)

  212091666 (D)

  212134013 (D)

  212134862 (G)

  RR Lyrae:

  211553019

  211565461

  211580649

  211598885

  211612680

  211620065

  211690919

  211691308

  211779259

  211779577

  211781167 maybe RR_Lyrae

  211691308

  211783365

  211820288

  211826447

  211842208

  211879654

  211884856

  211889811

  211891454

  211917094

  211918301

  211933496

  211966067

  211968795

  211971021

  211988670

  212029063

  212066778

  212074806

  212083439

  212106005

  212106539

  212130982

  212133146

  212143841

  228682496

  228682497

  228682498

  228682499

  228682500

  228682501

  228682502

  228682504

  228682505

  228682506

  228682507

  228682508

  228682509

  228682510

  228682511

  228682513

  228682513

  228682514

  Other:

  211546985 LPV

  211629697 regular inverse transits

  211686003 LPV

  211704298 LPV

  211730342 LPV

  211806798 LPV

  211819373 maybe Cepheid! Very interesting and seldom star type. Period around 5.182 days.

  211890655 LPV

  211896553 HB (HeartBeat binary)

  211911323 LPV

  211932036 just pulsating, but nice weird looking pattern in the LC

  211934173 looks like an EB, but the period is not constant, I don't know what's going on here???

  211973251 Asteroid crossings at BKJD 2314.97

  211977950 Asteroid crossings at BKJD 2308.14

  (earlier numbers not reported, no time for it, with some exceptions)

  211994890 Asteroid crossings at BKJD 2316.75, 2319.24, 2322.79, 2324.78

  211996783 Asteroid crossings at BKJD 2354.56

  211998489 Asteroid crossings at BKJD 2322.2

  211998490 Asteroid crossings at BKJD 2330.17

  212006447 Asteroid crossings at BKJD 2320.0, 2336.73, 2347.76 (or comet breakup parts?)

  212020650 Asteroid crossings at BKJD 2325.74

  212021131 Asteroid crossings at BKJD 2335.68

  212022229 Asteroid crossings at BKJD 2330.33

  212022746 Asteroid crossings at BKJD 2380.74

  212028281 just a few single points (but up to 4.0)

  212087677 Asteroid crossings at BKJD 2327.53

  212088849 interesting inverse transit at BKJD 2316.6

  212104651 maybe Asteroid crossings at BKJD 2316.35 and 2361.44

  212115220 Asteroid crossing at BKJD 2350.25

  212146679 Asteroid crossing at BKJD 2342.37

  212171121 maybe small Asteroid crossing at BKJD 2323.975

  212174021 Asteroid crossing at BKJD 2312.03

  212178048 Asteroid crossing at BKJD 2342.49

  228682493 maybe DN , around BKJD 2366

  228682494 maybe DN , around BKJD 2347

  Glitches:

  BKJD 2312.9 (examples: 212027371 212020391 )

  BKJD 2315.09 (examples 211943037 211933861 )

  BKJD 2334.9 dull glitch

  BKJD 2340.02

  BKJD 2353.15

  BKJD 2361.45

  Posted November 3, 2015 8:37 PM

• by JKD

  211310208 - maybe an Asteroid crossing at 2326.65 BKJD

  Posted November 3, 2015 9:55 PM

• by ajamyajax

  And also noting some duplicate 2MASS and color values in the C5 data:

  211307080 , 2MASS J08260902+0959396 , 10.509 , 10.165 , 10.090 , 0.344 , 0.075 , 'G9V'
  
  211307091 , 2MASS J08260902+0959396 , 10.509 , 10.165 , 10.090 , 0.344 , 0.075 , 'G9V'
  

  211559856 , 2MASS J09065430+1358472 , 10.461 , 9.963 , 9.865 , 0.498 , 0.098 , 'K3V'
  
  211559890 , 2MASS J09065430+1358472 , 10.461 , 9.963 , 9.865 , 0.498 , 0.098 , 'K3V'
  
  211559892 , 2MASS J09065430+1358472 , 10.461 , 9.963 , 9.865 , 0.498 , 0.098 , 'K3V'
  

  211806545 , 2MASS J08481954+1724346 , 10.641 , 10.126 , 10.003 , 0.515 , 0.123 , 'K3V'
  
  211806560 , 2MASS J08481954+1724346 , 10.641 , 10.126 , 10.003 , 0.515 , 0.123 , 'K3V'
  

  211770567 , 2MASS J08433991+1653549 , 8.139 , 7.835 , 7.835 , 0.304 , 0.0 , 'G3V'
  
  211770584 , 2MASS J08433991+1653549 , 8.139 , 7.835 , 7.835 , 0.304 , 0.0 , 'G3V'
  

  211811360 , 2MASS J08282283+1728432 , 7.934 , 7.477 , 7.393 , 0.457 , 0.084 , 'K2V'
  
  211811403 , 2MASS J08282283+1728432 , 7.934 , 7.477 , 7.393 , 0.457 , 0.084 , 'K2V'
  

  211835801 , 2MASS J08262508+1749257 , 8.434 , 8.225 , 8.174 , 0.209 , 0.051 , 'F6V'
  
  211835811 , 2MASS J08262508+1749257 , 8.434 , 8.225 , 8.174 , 0.209 , 0.051 , 'F6V'
  

  211944670 , 2MASS J08313759+1923395 , 7.509 , 6.894 , 6.603 , 0.615 , 0.291 , 'K6V'
  
  211944676 , 2MASS J08313759+1923395 , 7.509 , 6.894 , 6.603 , 0.615 , 0.291 , 'K6V'
  

  212017123 , 2MASS J08395330+2032212 , 9.552 , 9.353 , 9.268 , 0.199 , 0.085 , 'F5V'
  
  212017124 , 2MASS J08395330+2032212 , 9.552 , 9.353 , 9.268 , 0.199 , 0.085 , 'F5V'
  

  212154486 , 2MASS J08502705+2307526 , 8.176 , 7.998 , 8.169 , 0.178 , -0.171 , 'F6V'
  
  212154489 , 2MASS J08502705+2307526 , 8.176 , 7.998 , 8.169 , 0.178 , -0.171 , 'F6V'
  

  Posted November 5, 2015 3:23 PM

• by ajamyajax

  Re 211442297 from Martti's list: just checked this one first to look for a period which could be around 20.26 days. The quick stellar estimates I get vary quite a bit and with the deepest transit around 1.74%, this one could be an EB or BGEB. But will look again later with more corrected data.

  s1=2324.18 p1=20.26 d1=0.15 (3.6 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211442297 , 2MASS J08261282+1216550 , 12.108 , 11.760 , 11.724 , 0.348 , 0.036 , ('G8V', 0.94) , ('A3V', 2.0)

  au min-max 0.125 0.135
  
  stellar diameter in solar units min-max 0.61 0.69
  
  stellar mass in solar units min-max 0.635 0.8
  
  period in days min-max 20.256 20.257
  
  duration in hours min-max 3.518 3.691
  

  and from NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211442297 126.5534 12.2819 0.20 13.192 5
  
  211442215 126.5323 12.2806 74.53 14.118 5
  
  211443453 126.6057 12.3000 194.97 17.953 5
  

  

  Posted November 5, 2015 3:29 PM

• by ajamyajax

  Re 212110888 from Hans Martin's list: agree, this one looks like another nice possible hot gas giant candidate. Only up to 2350 BJD used for this fit with the MAST data because it takes extra work to clean everything up, but this should give us some idea of what the radius might be for a PC around a near Sun size star. And the transit could be either somewhat high impact, or the object could be luminous, or there could be limb darkening.. Will be interesting to see if the same shape here with more corrected data. And that could help us rule out a secondary or a binary of nearly equal size stars also.

  s1=2308.348 p1=2.996 d1=0.11 (2.64 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212110888 , 2MASS J08301891+2214092 , 10.528 , 10.258 , 10.193 , 0.27 , 0.065 , ('G2V', 1.0) , ('F9V', 1.14)

  au min-max 0.035 0.045
  
  stellar diameter in solar units min-max 0.835 1.155
  
  stellar mass in solar units min-max 0.635 1.36
  
  period in days min-max 2.99 3.001
  
  duration in hours min-max 2.541 2.736
  

  

  Posted November 5, 2015 3:36 PM

• by JKD

  211348419 - interesting RRL with a periodic increase of brightness intensity

  Posted November 5, 2015 7:22 PM

• by Shellface in response to Shellface's comment.

  Some mild assistance: the known Hot Jupiter hosts in M67 are EPID 211411531 and EPID 211416296, while the known hosts in Praesepe are EPID 211998346 and EPID 211936827. There is something like a ~35% probability that at least one of these four is transiting (without prior assumptions on the inclination distribution), so it's worth a look.

  The transit depth of the planet-hosting giant in M67 would be ~25 ppm, which is not realistically detectable.

  Posted November 5, 2015 9:11 PM

• by ajamyajax in response to Shellface's comment.

  211411531, 211416296: unfortunately not currently in the archive.

  211998346, 211936827: data available, but difficult to see any periods in the MAST data.

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211998346 , 2MASS J08414382+2013368 , 9.463 , 9.227 , 9.142 , 0.236 , 0.085 , ('F8V', 1.18) , ('G8V', 0.94)

  211936827 , 2MASS J08421149+1916373 , 10.660 , 10.242 , 10.173 , 0.418 , 0.069 , ('K1V', 0.86) , ('G2V', 1.0)

  Posted November 5, 2015 11:48 PM

• by Shellface in response to ajamyajax's comment.

  Well, the campaign notes do say that M67 got a super-stamp, or however you call it. I guess that'll take time to get to analyse.

  Posted November 6, 2015 5:27 PM

• by zoo3hans in response to Shellface's comment.

  Thanks Shellface,

  I already wondered what the EPIC numbers are for the known HJ. Obviously I didn't see anything special in the LC's of EPID 211998346 and EPID 211936827 (see my post on page 1 of this thread), but there are other HJ's around.

  Posted November 6, 2015 6:40 PM

• by Shellface in response to zoo3hans's comment.

  afaik there aren't any previously discovered transiting planets in the field, though I don't have a very good way to check. Optimistically, there's some new hot jupiters in here somewhere, though I warn that it's difficult to discern which transits are low-mass EBs in the raw data.

  Praesepe takes up quite a large amount of the field (obsoive), so I would expect there to be a lot of signals from the cluster. You seem to have turned up a lot of signals in the EPID ~2119nnnnn-2120nnnnn area, which is encouraging.

  Still gonna wait until data processing to do much analysis (hopefully with M67 in tow), but this is looking exciting. Keep at it, folks! I'll try get some C4 work done this weekend.

  Posted November 6, 2015 9:14 PM

• by ajamyajax

  Re 211309989 from Martti's list and an eb with a possible circumbinary planet: the good news so far is it seems a planet orbiting outside the binary pair is possible. These two stars seem similar in size but not quite. So my combined mass estimate based on the H-K colors produced a possible P=63.03. But note this is just a rough estimate.

  s1=2309.093 p1=7.5395 d1=0.13 (3.12 hours)

  s2=2312.658 p2=7.5395 d2=0.13 (3.12 hours)

  s3=2360.876 p3=? d3=0.17 (4.08 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211309989 , 2MASS J08284516+1003068 , 11.450 , 10.800 , 10.574 , 0.65 , 0.226 , ('M7V', 0.098) , ('M0V', 0.58)

  au min-max 0.065 0.08
  
  stellar diameter in solar units min-max 0.79 1.03
  
  stellar mass in solar units min-max 0.645 1.2
  
  period in days min-max 7.537 7.545
  
  duration in hours min-max 3.26 3.457
  

  Semi-Major Axis a (A.U.) = 0.319
  
  Stellar diameter ratio = 0.58
  
  Stellar mass ratio = 1.09
  
  Period ~= 63.03 days
  
  Duration ~= 4.08 hours
  

  
  

  Posted November 7, 2015 1:56 PM

• by ajamyajax

  Re 211993818 from Hans Martin's list: selected data plotted again for a better fit, but a fairly deep V-shape suggests any high impact object here would have to be fairly large also. For example a star ~1.12X R_sol would produce a PC radius estimate of ~17.24Re without high impact being considered. Also note this is a bright star with another nearby visually. See the Aladin Lite image, and NEA 2MASS data listing for more details.

  s1=2307.04 p1=8.9865 d1=0.185 (4.44 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211993818 , 2MASS J08244918+2009107 , 5.963 , 5.585 , 5.495 , 0.378 , 0.09 , ('G9V', 0.91) , ('G9V', 0.91)

  au min-max 0.08 0.1
  
  stellar diameter in solar units min-max 1.09 1.42
  
  stellar mass in solar units min-max 0.845 1.655
  
  period in days min-max 8.978 8.992
  
  duration in hours min-max 4.345 4.538
  

  and from NEA, 2MASS Objects within search area:
  
  2MASS Designation RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] J [mag] V or R [mag] Photometric flags
  

  • 08244918+2009107 126.204947 20.152994 0.07 5.963 7.35 AAA
    
    08245172+2009167 126.215527 20.154644 36.32 15.966 18.20 ABB
    
    08244865+2008341 126.202725 20.142817 37.38 8.539 8.61 AAA
    

  
  

  Posted November 7, 2015 1:58 PM

• by zoo3hans

  EPIC 211442297 from Martti's list: P=20.27 days, depth 0.017. U-shaped, probably a good planet candidate.

  Posted November 8, 2015 7:59 AM

• by zoo3hans

  EPIC 211509553 from Martti's list: P=20.365 days, depth 0.04, a bit on the deep side, but might still be a valid PC (I see no secondaries).

  Posted November 8, 2015 9:11 AM

• by zoo3hans

  EPIC 211543770 from Martti's list: here I cannot find a period, I think it's just bad residuals from the LC distortion

  Posted November 8, 2015 9:24 AM

• by Shellface

  EPID 211309989: It's obviously hard to say much with limited information, so I won't make any judgements of the reality of the signal.

  I can say that the EB looks fine. The transit/eclipse depths being roughly equal indicates the components have near-equal radii, and the transit depths suggest that the star crossings are approximately total. The presence of a large rotational signal is as expected for a short-period binary. aja's ephemerides indicates that the eccentricity of the binary is small, though non-zero, which is not unreasonable for the orbital period.

  Looking at various colour indices indicate the combined spectral type of the system is ~M1; the turn-around in J-H at ~K8 (followed by the re-turn at M4) is probably solely responsible for the J-H discrepancy.

  EPID 211993818: This is a very bright star for Kepler (V = 7.38), so it is naturally a high-priority target.

  Being so bright, it has a Henry Draper catalogue number (HD 70826) and Hipparcos observations (HIP 41232). However, its Hipparcos parallax is only 5.32 ± 0.92 mas, and the resulting luminosity clearly places it as a giant on the H-R diagram. The observed transit signal is far too deep (and short) to belong to a substellar companion to a giant, so this can quickly be dismissed as a false positive. However, this does not appear to be a giant EB either due to the short transit length, so some more investigation into the nature of the transits is warranted.

  Though there is indeed a nearby bright star (HD 70827), it is not likely to be the source of the transits as it is fainter than EPID 211993818 by 1.2 mag in the visible, and separated from it by 38", whereas Kepler contamination is typically from <8", unless the contaminator is much brighter than the target. This star also has Hipparcos observations (HIP 41231), and the Hipparcos parallax and proper motions are compatible with HD 70826, which suggests they are bound; this is confirmed by over 150 years of observations in the Washington Double Star catalogue (WDS), which shows that the two stars have negligible relative motion. This star has a spectral type of ~A3, based on its B-V; SIMBAD lists it as A2m, but I suspect that is due to confusion.

  Looking through the literature, there are a few studies which give some important information. Ginestet & Carquillat (2002) observe HD 70826 spectroscopically in the near-UV, in response on some previous inferences of multiple stellar components by spectroscopy, and observe the lines of 2 Am stars, with spectral types of ~A2m. As these are significantly bluer than the giant (G7), they significantly contribute to the stellar magnitudes in bluer bands; the combined B-V of the system is 0.63 (G2), which is significantly earlier than the expected value of a G7 star (~0.72) as the A-type components contribute substantial amounts of the overall flux. They calculate a magnitude difference between the giant and the combined flux of the A-type stars of +0.87, which corresponds to a luminosity ratio of 1 : 0.44.

  Carquillat et al. (2005) follow up on their previous work with RV observations of the giant by CORAVEL. They find that the star is a SB1 (single-lined spectroscopic binary, in the visible) with a period of 3900 days. For such a long period, the RV semi-amplitude is unusually high, which leads to a mass function greater than 1. For sensible values for the mass of the giant, this leads to a companion mass greater than that of the giant, which is illogical; if the companion is a more massive star, then why is it not a giant? The authors conclude that the companion is very likely to be composed of the same two stars observed in the UV, which then orbit the giant with a 3900-day period.

  It seems like the logical conclusion, then, to assume that the transits are due to the A-type components of this system. Aside from the general improbability of there being other stars in the aperture, this is supported by how both components are Am; this refers to extreme over-abundances of some A-type stars in certain elements, on order of 10 times solar, several times greater than the highest real metallicity abundances. This phenomenon is extremely strongly related to close binarity, which decreases the rotational velocity of the star(s), prompting the differentiation of elements in the atmosphere that brings some elements close to the surface in high abundance. That both A-type components are Am suggests that they are responsible for the Am nature of of each other.

  If this is true, then the true period of the binary may or may not be double the observed value (17.97d). However, the transits appear to be grazing (they are rather short, and seem to be shallow even when considering the large third light contribution), so it is possible that the 8.99d period is correct if there is a substantial amount of eccentricity in the binary, which may or may not be likely.

  With some extra work - in particular some time-resolved radial velocities for the Am stars, and perhaps resolved imaging of the giant and the Am stars - it may be possible to comprehensively solve the orbital parameters of this triple in a quadruple. Though a planetary false positive, this is still a system that warrants interest.

  Posted November 8, 2015 9:17 PM

• by ajamyajax

  211311380 from Martti's list and a possible MPC: is a tough one to figure. There is an intriguing possible transit overlap around 2353.9x that is causing a greater flux reduction than the depth of the first event. And others could be affect by glitches or the corrective software algorithm (note the possible inverted transit pictured below).

  The stellar parameters I get do vary however. Yet an estimate of ~12Re for the larger possible transit using a ~2.8X R_sol star seems reasonable. Maybe this is a brown dwarf system(?) Edit: of course that radius could mean a Jupiter also. The nearby EPIC's didn't show any similar events, but there are other stars of course. So if not glitches, maybe this light curve has several blended transit sources is my guess here.

  s1=2309.012 p1=44.95 d1=0.52 (12.48 hours)

  s2=2312.885 p2=20.485 d2=0.19 (4.56 hours)

  s3=2319.275 p3=34.79 d3=0.21 (5.04 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211311380 , 2MASS J08262784+1004493 , 7.982 , 7.786 , 7.722 , 0.196 , 0.064 , ('F5V', 1.32) , ('F9V', 1.14)

  au min-max 0.34 0.37
  
  stellar diameter in solar units min-max 2.635 2.905
  
  stellar mass in solar units min-max 2.595 3.345
  
  period in days min-max 44.942 44.957
  
  duration in hours min-max 12.384 12.578
  

  au min-max 0.145 0.155
  
  stellar diameter in solar units min-max 0.89 0.99
  
  stellar mass in solar units min-max 0.97 1.185
  
  period in days min-max 20.475 20.477
  
  duration in hours min-max 4.467 4.655
  

  au min-max 0.205 0.215
  
  stellar diameter in solar units min-max 0.82 0.89
  
  stellar mass in solar units min-max 0.95 1.095
  
  period in days min-max 34.782 34.797
  
  duration in hours min-max 4.952 5.133
  

  ...

  and from NEA, 2MASS Objects within search area:
  
  2MASS Designation RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] J [mag] V or R [mag] Photometric flags
  

  • 08262784+1004493 126.616024 10.080387 0.08 7.982 8.93 AAA
    
    08262726+1005077 126.613621 10.085494 20.32 13.112 14.50 AAA
    
    08262953+1004314 126.623057 10.075389 30.67 16.141 18.10 BCD
    
    08262708+1004114 126.612870 10.069861 39.49 15.147 17.10 AAB
    
    08263055+1004503 126.627294 10.080640 39.89 13.051 15.60 AAA
    
    08262687+1003587 126.611968 10.066311 52.66 15.010 16.20 AAB
    
    08263141+1005400 126.630890 10.094467 73.09 15.777 16.80 AB
    
    ...

  also from NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211311380 126.6160 10.0804 0.17 9.128 5
  
  211310019 126.6151 10.0524 100.77 13.757 5
  
  211309924 126.6290 10.0503 117.62 13.417 5
  
  211313909 126.6166 10.1318 185.13 13.404 5
  
  211310806 126.5645 10.0684 187.71 14.345 5
  

  ...

  
  
  
  
  

  Posted November 9, 2015 2:41 PM

• by ajamyajax

  Re 211929937 from Hans Martin's list: agree, looks like a fine hot Jupiter candidate that deserves a proper follow-up. My radius estimate with a ~0.82x R_sol star.

  s1=2309.41 p1=3.4767 d1=0.10 (2.4 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211929937 , 2MASS J08364282+1910257 , 12.873 , 12.454 , 12.351 , 0.419 , 0.103 , ('K1V', 0.86) , ('K2V', 0.85)

  au min-max 0.04 0.045
  
  stellar diameter in solar units min-max 0.745 0.91
  
  stellar mass in solar units min-max 0.705 1.01
  
  period in days min-max 3.468 3.487
  
  duration in hours min-max 2.303 2.499
  

  

  Posted November 9, 2015 2:44 PM

• by ajamyajax

  Re 211319617 from Martti's list: yes could be contamination, but this one deserves a chance as a sub-Neptune planet candidate in my opinion. Radius estimate with a ~0.75X R_sol star; could be a bit larger.

  s1=2310.39 p1=8.867 d1=0.125 (3.0 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211319617 , 2MASS J08255135+1014491 , 11.146 , 10.747 , 10.677 , 0.399 , 0.07 , ('K0V', 0.89) , ('G1V', 1.07)

  au min-max 0.065 0.08
  
  stellar diameter in solar units min-max 0.6 0.785
  
  stellar mass in solar units min-max 0.465 0.87
  
  period in days min-max 8.861 8.876
  
  duration in hours min-max 2.905 3.095
  

  

  Posted November 9, 2015 8:49 PM

• by ajamyajax

  Re 211770867 from Hans Martin's list: eccentric secondary transit here which usually indicates an eccentric binary. Also with a ~1.12X R_sol star, a possible radius for this object might be ~18Re (+/-).

  s1=2314.872 p1=27.693 d1=0.30 (7.2 hours)

  s2=2325.94 p2=27.693 d2=0.30 (7.2 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211770867 , 2MASS J08120543+1654108 , 11.185 , 10.951 , 10.881 , 0.234 , 0.07 , ('F8V', 1.18) , ('G1V', 1.07)

  

  Posted November 9, 2015 8:51 PM

• by JKD

  211342524 - EB with p=28.88d

  Posted November 9, 2015 9:24 PM

• by ajamyajax

  Re 211351816 from Martti's list: some sign of a blended binary here in an alternating fit plus different stellar estimates.

  s1=2309.02 p1=8.416 d1=0.17 (4.08 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211351816 , 2MASS J08310308+1050513 , 10.694 , 10.177 , 10.035 , 0.517 , 0.142 , ('K3V', 0.81) , ('K5V', 0.75)

  au min-max 0.075 0.095
  
  stellar diameter in solar units min-max 1.0 1.325
  
  stellar mass in solar units min-max 0.795 1.615
  
  period in days min-max 8.404 8.422
  
  duration in hours min-max 3.985 4.179
  

  

  Posted November 11, 2015 2:11 PM

• by ajamyajax

  Re 211359660 from Martti's list: looks like a pretty good sub-Neptune candidate in my opinion. A 0.82x R_sol star used for this radius estimate, but perhaps it should be a bit smaller.

  s1=2308.205 p1=4.7375 d1=0.11 (2.64 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211359660 , 2MASS J08404327+1058585 , 10.408 , 9.994 , 9.913 , 0.414 , 0.081 , K , ('K1V', 0.86) , ('G6V', 0.97)

  au min-max 0.045 0.055
  
  stellar diameter in solar units min-max 0.68 0.89
  
  stellar mass in solar units min-max 0.54 0.99
  
  period in days min-max 4.731 4.747
  
  duration in hours min-max 2.543 2.737
  

  

  Posted November 11, 2015 2:13 PM

• by ajamyajax

  Re 212164470 from Hans Martin's list: possible blended super-Earth planet candidate which is good to see because they seem to be less common. A ~0.75X R_sol star used for this estimate.

  s1=2311.861 p1=7.805 d1=0.125 (3.0 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212164470 , 2MASS J08391527+2321269 , 11.502 , 11.246 , 11.149 , 0.256 , 0.097 , ('F9V', 1.14) , ('K1V', 0.86)

  au min-max 0.065 0.075
  
  stellar diameter in solar units min-max 0.69 0.82
  
  stellar mass in solar units min-max 0.6 0.925
  
  period in days min-max 7.8 7.814
  
  duration in hours min-max 2.952 3.038
  

  

  Posted November 13, 2015 12:21 AM

• by ajamyajax

  Re 212132195 from Hans Martin's list: only two transits, but looks pretty convincing as a mini-gas giant planet candidate. ~0.78X R_sol star estimate.

  s1=2331.40 p1=26.2 d1=0.18 (4.32 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212132195 , 2MASS J08235691+2239467 , 10.128 , 9.566 , 9.501 , 0.562 , 0.065 , ('K6V', 0.7) , ('F9V', 1.14)

  au min-max 0.17 0.17
  
  stellar diameter in solar units min-max 0.77 0.805
  
  stellar mass in solar units min-max 0.955 0.955
  
  period in days min-max 26.198 26.198
  
  duration in hours min-max 4.223 4.415
  

  

  Posted November 13, 2015 2:42 AM

• by ajamyajax

  Re 211391664 from Martti's list: possible inflated Neptune planet candidate around what could be a fairly hot star using ~1.36x R_sol for this estimate.

  s1=2313.013 p1=10.129 d1=0.2175 (5.22 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211391664 , 2MASS J08255719+1130402 , 11.124 , 10.905 , 10.869 , 0.219 , 0.036 , ('F7V', 1.21) , ('A3V', 2.0)

  au min-max 0.095 0.11
  
  stellar diameter in solar units min-max 1.35 1.62
  
  stellar mass in solar units min-max 1.115 1.73
  
  period in days min-max 10.128 10.131
  
  duration in hours min-max 5.123 5.318
  

  

  Posted November 13, 2015 3:47 PM

• by JKD

  211371825 - speculative PC

  Signal: 2344.70 BKJD

  Period: unknown

  Duration: 5.39 Hrs

  Signal Depth: 2139 ppm

  Posted November 13, 2015 8:03 PM

• by JKD

  211372074 - likely a PC

  Signal: 2340.016 BKJD

  Period: unknown

  Duration: 6.865 Hours

  Signal Depth: 1678 ppm

  Posted November 13, 2015 8:24 PM

• by JKD

  211373370 - PC

  Signal : 2345.63 BKJD

  Period: unknown

  Duration: 2.94 Hours

  Signal Depth: 1785 ppm

  Posted November 13, 2015 8:35 PM

• by JKD

  211374104 - PC (maybe a Ring Candidate)

  Signal: 2317.68 BKJD

  Period: unknown

  Duration: 11.768 Hours

  Signal Depth: 2114 ppm

  Posted November 13, 2015 8:51 PM

• by ajamyajax

  Re 211399359 from Martti's list: could be another hot Jupiter planet candidate here. Fairly nice uniform fit and no obvious signs of a secondary in this data. The radius estimate for a ~0.73X R_sol star.

  s1=2308.42 p1=3.1147 d1=0.09 (2.16 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211399359 , 2MASS J08321610+1137504 , 12.974 , 12.494 , 12.391 , 0.48 , 0.103 , ('K2V', 0.85) , ('K2V', 0.85)

  au min-max 0.035 0.04
  
  stellar diameter in solar units min-max 0.655 0.815
  
  stellar mass in solar units min-max 0.59 0.885
  
  period in days min-max 3.106 3.124
  
  duration in hours min-max 2.065 2.259
  

  

  Posted November 14, 2015 3:24 PM

• by ajamyajax

  Re 211413752 from Martti's list: and speculative, but perhaps a blended mini-gas giant here using a 0.75X R_sol star estimate.

  s1=2307.847 p1=9.327 d1=0.13 (3.12 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211413752 , 2MASS J08545028+1150537 , 12.158 , 11.720 , 11.639 , 0.438 , 0.081 , ('K3V', 0.81) , ('G6V', 0.97)

  au min-max 0.07 0.085
  
  stellar diameter in solar units min-max 0.64 0.82
  
  stellar mass in solar units min-max 0.525 0.94
  
  period in days min-max 9.328 9.336
  
  duration in hours min-max 3.03 3.216
  

  

  Posted November 17, 2015 11:31 PM

• by JKD

  KID 211390677 - was already mentioned on page 1 by Martti as a potential planet candidate at ~ 2318.75 BKJD.
  Looks somehow special and is worth for further analysis especially with regard to the transit duration of ~32.26 Hours and a signal depth of ~7100 ppm - maybe it’s not a PC

  Posted November 18, 2015 7:48 PM

• by ajamyajax in response to JKD's comment.

  Re 211390677 from Martti's list: well a calculated guess of what this single transit might be is a long-period sub-Saturn planet candidate. Note the stellar constraints are based only on these colors, but the star does look DSS colored white in Aladin Lite which helps.

  s1=2318.79 p1=15134.66 d1=1.55 (37.2 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211390677 , 2MASS J08304892+1129403 , 11.776 , 11.247 , 11.162 , 0.529 , 0.085 , ('K3V', 0.81) , ('G8V', 0.94)

  Semi-Major Axis a (A.U.) = 11.73
  
  Stellar diameter ratio = 0.81
  
  Stellar mass ratio = 0.94
  
  Period ~= 15134.66 days
  
  Duration ~= 37.2 hours
  

  For Reference this period ~= 41.44 years
  
  Jupiter P=11.8 years, 5.20 AU
  
  Saturn P=29.5 years, 9.54 AU
  
  Neptune P=165 years, 30.06 AU
  

  
  

  Posted November 18, 2015 10:02 PM

• by ajamyajax

  Re 212099230 from Hans Martin's list: possible irradiated mini-gas giant or a blended binary with truncated transits. 0.82X R_sol star for this estimate.

  s1=2308.96 p1=7.112 d1=0.13 (3.12 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212099230 , 2MASS J08321766+2200217 , 9.343 , 8.998 , 8.873 , 0.345 , 0.125 , ('G8V', 0.94) , ('K3V', 0.81)

  au min-max 0.06 0.075
  
  stellar diameter in solar units min-max 0.72 0.955
  
  stellar mass in solar units min-max 0.57 1.115
  
  period in days min-max 7.105 7.121
  
  duration in hours min-max 3.024 3.22
  

  
  

  Posted November 18, 2015 10:06 PM

• by ajamyajax

  Re 212011230 from Hans Martin's list: this single transit could in theory have a period close to a repeat being visible, maybe just beyond the range of K2 data we have to view. I got 0.73X R_sol as a stellar estimate which also produces another sub-Saturn planet candidate. Also assuming it's not a glitch.

  s1=2332.488 p1=51.63 d1=0.22 (5.28 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212011230 , 2MASS J09045782+2026270 , 10.862 , 10.330 , 10.240 , 0.532 , 0.09 , ('K3V', 0.81) , ('G9V', 0.91)

  Semi-Major Axis a (A.U.) = 0.254
  
  Stellar diameter ratio = 0.73
  
  Stellar mass ratio = 0.82
  
  Period ~= 51.63 days
  
  Duration ~= 5.28 hours
  

  

  Posted November 20, 2015 1:27 AM

• by ajamyajax

  Re 211418290 from Martti's list: well, ragged transits in the MAST data and maybe a sign of a secondary here. Also a long duration for this short of a period. So this could be an EB if not a giant. But we should check this LC again with more corrected data.

  s1=2308.807 p1=5.0335 d1=0.34 (8.16 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211418290 , 2MASS J08371255+1154567 , 10.303 , 9.877 , 9.755 , 0.426 , 0.122 , ('K1V', 0.86) , ('K3V', 0.81)

  au min-max 0.085 0.085
  
  stellar diameter in solar units min-max 3.82 3.85
  
  stellar mass in solar units min-max 3.225 3.245
  
  period in days min-max 5.025 5.04
  
  duration in hours min-max 8.06 8.125
  

  

  Posted November 20, 2015 1:29 AM

• by ajamyajax

  Re 212008766 from Hans Martin's list: appears to be either a mini-gas giant or a blended binary. Aladin Lite does show a fairly busy neighborhood (not pictured). 0.80x R_sol stellar estimate.

  s1=2312.12 p1=14.13 d1=0.15 (3.60 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212008766 , 2MASS J08370778+2023577 , 11.507 , 11.051 , 10.986 , 0.456 , 0.065 , ('K2V', 0.85) , ('F9V', 1.14)

  au min-max 0.11 0.115
  
  stellar diameter in solar units min-max 0.77 0.845
  
  stellar mass in solar units min-max 0.89 1.015
  
  period in days min-max 14.125 14.139
  
  duration in hours min-max 3.519 3.698
  

  

  Posted November 20, 2015 1:31 AM

• by JKD

  211421297 - speculative Planet Candidate in a glitch area

  s1 = 2340.01 BKJD; d1 = 6.86 Hrs; p1 = ?; Flux = 1874 ppm

  Posted November 20, 2015 6:30 AM

• by JKD

  211438539 - maybe a long-period PC

  s1 = 2342.366 BKJD; p1 = ???; Transit time ~20.59 hrs; Flux = 3255 ppm

  Posted November 20, 2015 8:02 PM

• by JKD in response to zoo3hans's comment.

  EPIC 211442297 - seems to be a PC

  3 repeats with p~20.3 d and

  comparable Flux ~17300 ppm

  Posted November 20, 2015 8:21 PM

• by JKD

  211467651 - pot PC

  transit at ~2350.76 BKJD, duration ~8.82 hrs, signal depth ~3175 ppm

  Posted November 21, 2015 10:02 PM

• by JKD

  211503363 - already mentioned on page 1 as a PC

  It is another long-period PC - Signal: 2364.49 BKJD, Duration: 24.51 hrs, Signal Depth: 5073 ppm

  having an interesting tiny signal (Moon ?) at 2362.89 BKJD, Duration ~4.41 hrs and a Signal Depth of ~1387 ppm

  Posted November 22, 2015 2:04 PM

• by JKD

  211617231 - looks like a regular EB with p=31.75d

  Posted November 23, 2015 9:29 PM

• by JKD

  211805106 - likely an EB

  secondary transit at ~2343.20 BKJD, Duration ~30.40 hrs

  Posted November 29, 2015 7:00 PM

• by ajamyajax

  Re 211808055 from Hans Martin's list and from Shaya's post on CFOP-K2: this one appears to be contaminated by EB 211807843 only 20.54 arc seconds away. The ephemeris marked is from the 211808055 transit. Also note the sign of a larger star in my stellar estimates. So if we can rule out a giant in these cases, the transit is more likely to be an EB or BGEB in my humble opinion.

  s1=2309.61 p1=3.3823 d1=0.235 (5.64 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211808055 , 2MASS J08360827+1725483 , 12.545 , 12.200 , 12.141 , 0.345 , 0.059 , ('G8V', 0.94) , ('F6V', 1.25)

  au min-max 0.055 0.07
  
  stellar diameter in solar units min-max 2.525 3.345
  
  stellar mass in solar units min-max 1.93 4.02
  
  period in days min-max 3.373 3.392
  
  duration in hours min-max 5.54 5.739
  

  ...

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211808055 129.0345 17.4301 0.15 13.741 5
  
  211807843 129.0293 17.4272 20.54 11.443 5
  

  

  Posted December 1, 2015 2:33 PM

• by ajamyajax

  Re 211418729 from Martti's list: sparse data with only several clean transit looks here, but this one deserves a chance as a Jupiter PC in my view if a ~0.90x R_sol star. There is no sign of transit contamination from nearby NEA target 211418174, but it is still a possible blended light source.

  s1=2307.327 p1=11.39 d1=0.16 (3.84 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211418729 , 2MASS J08313191+1155202 , 12.835 , 12.386 , 12.304 , 0.449 , 0.082 , ('K2V', 0.85) , ('G6V', 0.97)

  au min-max 0.09 0.105
  
  stellar diameter in solar units min-max 0.835 1.02
  
  stellar mass in solar units min-max 0.75 1.19
  
  period in days min-max 11.381 11.392
  
  duration in hours min-max 3.746 3.939
  

  And from NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211418729 127.8830 11.9223 0.18 14.286 5
  
  211418174 127.8752 11.9140 40.41 13.727 5
  

  

  Posted December 2, 2015 12:36 AM

• by ajamyajax

  Re 211978988 from Hans Martin's list: two or more possible planet candidates here with a second transit looking really blended at times and maybe high-impact. A bit more speculative also, but these stellar parameters are fairly consistent for a ~0.85X R_sol star estimate.

  s1=2319.715 p1=36.556 d1=0.24 (5.76 hours)

  s2=2313.457 p2=10.293 d2=0.133 (3.20 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211978988 , 2MASS J08415934+1954599 , 11.516 , 11.249 , 11.170 , 0.267 , 0.079 , ('G0V', 1.09) , ('G6V', 0.97)

  au min-max 0.19 0.21
  
  stellar diameter in solar units min-max 0.83 0.945
  
  stellar mass in solar units min-max 0.685 0.925
  
  period in days min-max 36.547 36.549
  
  duration in hours min-max 5.668 5.854
  

  au min-max 0.08 0.095
  
  stellar diameter in solar units min-max 0.69 0.865
  
  stellar mass in solar units min-max 0.645 1.08
  
  period in days min-max 10.291 10.291
  
  duration in hours min-max 3.159 3.335
  

  Edit: these more blended transit ranges were remove from the P=10.29x fit:
  
  2333.980 to 2334.1137 BJD
  
  2354.570 to 2354.7037 BJD
  
  2364.865 to 2364.9987 BJD
  

  
  
  

  Posted December 2, 2015 4:58 PM

• by ajamyajax

  Re 211432167 from Martti's list: this is HD 75638 per VSX which is an F0 EB. Just some more info: transit depth ~1.46%, also faint signs of a secondary. There is a close visual companion as seen in this AladinLite image, but it isn't nearby 211431505 in the NEA search list below. All the nearby EPIC targets on this NEA list are fairly quiet actually with no sign of transit contamination.

  s1=2308.93 p1=5.8175 d1=0.14 (3.36 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211432167 , 2MASS J08512734+1207406 , 7.285 , 7.134 , 7.086 , 0.151 , 0.048 , ('F3V', 1.43) , ('F1V', 1.5)

  au min-max 0.055 0.07
  
  stellar diameter in solar units min-max 0.87 1.17
  
  stellar mass in solar units min-max 0.655 1.355
  
  period in days min-max 5.811 5.824
  
  duration in hours min-max 3.261 3.457
  

  And from NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211432167 132.8638 12.1279 0.07 8.550 5
  
  211431505 132.8715 12.1171 47.44 16.034 5
  
  211432922 132.8720 12.1395 50.69 18.170 5
  
  211432425 132.8463 12.1317 63.10 14.929 5
  
  211433158 132.8501 12.1430 72.63 17.173 5
  
  211433771 132.8664 12.1519 86.81 16.347 5
  
  228682476 132.8527 12.1502 89.23 19.5 5
  
  228682450 132.8380 12.1272 90.87 18.6 5
  
  211433807 132.8522 12.1523 96.81 18.527 5
  
  228682442 132.8404 12.1116 101.19 19.8 5
  
  211430475 132.8478 12.1011 111.78 18.641 5
  
  211430343 132.8512 12.0990 113.17 15.532 5
  
  211430252 132.8824 12.0971 128.81 15.655 5
  
  211430661 132.8938 12.1041 136.01 17.671 5
  
  211433632 132.8979 12.1498 143.54 16.941 5
  
  211429656 132.8589 12.0875 146.53 18.790 5
  

  Per VSX:

  Dist. ' Name AUID Coords (J2000) Const. Var. type Period (d) Mag. range

  0.03 Variable HD 75638 -- 08 51 27.44 +12 07 40.7 Cnc EA 5.8167 10.7 (0.09) V

  http://www.aavso.org/vsx/index.php?view=detail.top&oid=225717

  
  

  Posted December 2, 2015 10:34 PM

• by ajamyajax

  Re 211978909 from Hans Martin's list: per VSX, this LC could be contaminated by KP 103608 which is listed as a pulsating variable (which are not quite periodic, so these periods could be seen as slightly different).

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211978909 , 2MASS J08433738+1954563 , 11.867 , 11.389 , 11.328 , 0.478 , 0.061 , ('K2V', 0.85) , ('F7V', 1.21)

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211978909 130.9058 19.9157 0.14 13.182 5
  
  211980250 130.9061 19.9366 75.39 12.558 5
  
  211977511 130.9089 19.8934 80.82 12.053 5
  
  211977426 130.9342 19.8919 128.68 11.693 5
  

  Per VSX:

  Dist. ' Name AUID Coords (J2000) Const. Var. type Period (d) Mag. range

  1.25 Variable KP 103608 -- 08 43 37.46 +19 56 11.7 Cnc PULS 8.8821 12.353 - ? R

  

  Posted December 3, 2015 12:22 AM

• by zoo3hans in response to ajamyajax's comment.

  Dear Mark

  EPIC 211978988. Well, the second candidate (with P=10.293 days) does not look very convincing in LcViewer. The two largest signals are bordering small gaps and may be spurious. I might see another candidate with P=13.6 days at 2312.2, 2330.0, 2344.4, 2358.0, 2371.6 though.

  Yours, Hans Martin

  Posted December 3, 2015 9:37 AM

• by ajamyajax in response to zoo3hans's comment.

  That's fine, let's both take another look when there is more corrected data available and see what is apparent then.

  Posted December 3, 2015 8:57 PM

• by ajamyajax

  Re 211490999 from Martti's list: and limited transit data shown but a possible sub-Neptune planet candidate here. I didn't see any obvious sign of contamination. 1.05x R_sol star estimate.

  s1=2313.33 p1=9.846 d1=0.165 (3.96 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211490999 , 2MASS J08431171+1300345 , 12.302 , 11.918 , 11.870 , 0.384 , 0.048 , ('G9V', 0.91) , ('F1V', 1.5)

  au min-max 0.08 0.1
  
  stellar diameter in solar units min-max 0.885 1.155
  
  stellar mass in solar units min-max 0.705 1.375
  
  period in days min-max 9.837 9.85
  
  duration in hours min-max 3.871 4.057
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211490999 130.7988 13.0096 0.17 13.416 5
  
  211491423 130.7788 13.0153 73.26 13.150 5
  

  

  Posted December 3, 2015 9:01 PM

• by ajamyajax

  Re 211972200 from Hans Martin's list as an HJ or EB: a ragged LC but still interesting because my duration-based orbit calculation suggests a low mass/high radius giant. Seems like that would be unusual if an EB configuration. Maybe Shellface could take a look at this one later.

  s1=2307.79 p1=3.153 d1=0.48 (11.52 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211972200 , 2MASS J08210547+1948426 , 11.625 , 11.044 , 10.951 , 0.581 , 0.093 , ('K5V', 0.75) , ('K0V', 0.89)

  Semi-Major Axis a (A.U.) = 0.0442
  
  Stellar diameter ratio = 4.54
  
  Stellar mass ratio = 1.16
  
  Period ~= 3.15 days
  
  Duration ~= 11.52 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211972200 125.2728 19.8118 0.15 13.200 5
  
  211971961 125.3156 19.8079 145.66 13.783 5
  

  

  Posted December 4, 2015 5:52 PM

• by ajamyajax

  Re 211945201 from Hans Martin's list: a possible Neptune here with a limb-darkening effect on a near Sun-size star, or a blended binary with truncated transits. 0.96X R_sol used for this fit.

  s1=2325.83 p1=19.49 d1=0.19 (4.56 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211945201 , 2MASS J09061775+1924080 , 9.144 , 8.908 , 8.837 , 0.236 , 0.071 , ('F8V', 1.18) , ('G1V', 1.07)

  au min-max 0.145 0.15
  
  stellar diameter in solar units min-max 0.935 1.005
  
  stellar mass in solar units min-max 1.07 1.185
  
  period in days min-max 19.492 19.496
  
  duration in hours min-max 4.463 4.648
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211945201 136.5740 19.4023 0.19 10.115 5
  
  211944999 136.5477 19.3991 89.94 13.111 5
  
  211942783 136.5768 19.3665 129.06 12.904 5
  

  

  Posted December 4, 2015 5:54 PM

• by JKD

  211821192 - worth to be checked again

  I agree with zoo3hans, who has already mentioned this PC on page 1. Details here again:

  signal: 2344.24 BKJD

  period: unknown

  duration: 10.7 hrs

  depth: 1240 ppm

  Posted December 4, 2015 7:15 PM

• by JKD

  211892898 -worth to be checked again

  I agree with zoo3hans, who has already mentioned this PC on page 1. Details here again:

  signal: 2356. 40 BKJD

  period: unknown

  duration: 63.74 hrs

  depth: 8922 ppm

  Posted December 4, 2015 9:35 PM

• by ajamyajax

  Re 211821192 from HM's list and JKD's mention: there is a similar but shallower such event in the NEA targets listed below (especially 211822957), so this one could be either a glitch or some sort of contamination. And both of you can do this sort of background checking yourselves, too.

  s1=2344.205 p1=? d1=0.25 (6.0 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211821192 , 2MASS J08270567+1737055 , 11.527 , 11.195 , 11.123 , 0.332 , 0.072 , ('G6V', 0.97) , ('G1V', 1.07)

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211821192 126.7737 17.6182 0.14 12.581 5
  
  211821580 126.7543 17.6237 69.31 13.006 5
  
  211822957 126.7645 17.6422 91.90 11.662 5
  
  211823035 126.7822 17.6432 94.60 16.582 5
  

  Posted December 5, 2015 12:59 PM

• by ajamyajax

  Re 211892898 from HM's list and JKD's mention: this one seems planetary, hope it's not a glitch but always possible with single transits. If a star ~0.75x R_sol, this could be a sub-Saturn candidate with a radius ~7.41Re. And these long period parameters are just a calculated guess based on the colors here.

  s1=2356.4 p1=? d1=2.5 (60.0 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211892898 , 2MASS J08433463+1837199 , 10.259 , 9.704 , 9.601 , 0.555 , 0.103 , ('K4V', 0.78) , ('K2V', 0.85)

  Semi-Major Axis a (A.U.) = 31.43
  
  Stellar diameter ratio = 0.75
  
  Stellar mass ratio = 0.83
  
  Period ~= 70642.65 days
  
  Duration ~= 60.0 hours
  

  For Reference this period ~= 193.41 years
  
  Jupiter P=11.8 years, 5.20 AU
  
  Saturn P=29.5 years, 9.54 AU
  
  Neptune P=165 years, 30.06 AU
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211892898 130.8943 18.6222 0.01 11.773 5
  
  211893639 130.9313 18.6332 132.30 16.573 5
  

  

  Posted December 5, 2015 1:01 PM

• by ajamyajax

  Re 211503363 from Martti's list: this one looks much like the other longer duration single transits posted. Same PC chances, too. So maybe a 5.28Re planet candidate here if a 0.73X R_sol star.

  s1=2364.51 p1=3489.44 d1=0.90 (21.6 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211503363 , 2MASS J08300163+1311116 , 11.788 , 11.262 , 11.249 , 0.526 , 0.013 , ('K3V', 0.81) , ('B8V', 3.4)

  Semi-Major Axis a (A.U.) = 4.197
  
  Stellar diameter ratio = 0.73
  
  Stellar mass ratio = 0.81
  
  Period ~= 3489.44 days
  
  Duration ~= 21.6 hours
  

  For Reference this period ~= 9.55 years
  
  Jupiter P=11.8 years, 5.20 AU
  
  Saturn P=29.5 years, 9.54 AU
  
  Neptune P=165 years, 30.06 AU
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211503363 127.5068 13.1866 0.12 13.221 5
  
  211503731 127.5049 13.1915 18.97 14.715 5
  
  211505246 127.5094 13.2132 96.32 12.442 5
  

  Posted December 7, 2015 5:16 PM

• by ajamyajax

  Re 211923431 from Hans Martin's list: another sub-Neptune planet candidate perhaps, if a ~0.80X R_sol star.

  s1=2310.83 p1=29.73 d1=0.19 (4.56 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211923431 , 2MASS J08314496+1904288 , 12.927 , 12.491 , 12.435 , 0.436 , 0.056 , ('K3V', 0.81) , ('F5V', 1.32)

  au min-max 0.18 0.19
  
  stellar diameter in solar units min-max 0.76 0.835
  
  stellar mass in solar units min-max 0.88 1.035
  
  period in days min-max 29.734 29.734
  
  duration in hours min-max 4.468 4.651
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211923431 127.9374 19.0746 0.21 14.101 5
  
  211925262 127.9506 19.1022 108.97 15.499 5
  
  211920892 127.9454 19.0381 134.37 13.101 5
  
  211924873 127.9715 19.0962 139.71 11.224 5
  

  

  Posted December 7, 2015 5:18 PM

• by ajamyajax

  Re 211919004 from Hans Martin's list: sparse transit data with only some of it useful, but my model fit suggests a Neptune planet candidate is possible here. Another LC to revisit with more corrected data. 1.04X R_sol estimate.

  s1=2316.09 p1=11.725 d1=0.17 (4.08 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211919004 , 2MASS J08390649+1900360 , 11.811 , 11.372 , 11.300 , 0.439 , 0.072 , ('K3V', 0.81) , ('G1V', 1.07)

  au min-max 0.1 0.105
  
  stellar diameter in solar units min-max 0.955 1.05
  
  stellar mass in solar units min-max 0.97 1.125
  
  period in days min-max 11.716 11.727
  
  duration in hours min-max 3.986 4.174
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211919004 129.7770 19.0100 0.18 13.131 5
  
  211921414 129.7692 19.0459 131.89 11.439 5
  
  211920732 129.7460 19.0359 140.87 12.700 5
  

  

  Posted December 7, 2015 5:20 PM

• by ajamyajax

  Re 211916756 from Hans Martin's list: another V-shaped transit that could be a high-impact gas giant or a sign of a binary. 0.71X R_sol star estimate.

  s1=2307.747 p1=10.134 d1=0.135 (3.24 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211916756 , 2MASS J08372705+1858360 , 13.312 , 12.738 , 12.474 , 0.574 , 0.264 , ('K6V', 0.7) , ('M3V', 0.4)

  au min-max 0.08 0.08
  
  stellar diameter in solar units min-max 0.7 0.74
  
  stellar mass in solar units min-max 0.665 0.665
  
  period in days min-max 10.135 10.135
  
  duration in hours min-max 3.156 3.337
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211916756 129.3627 18.9767 0.16 15.498 5
  

  

  Posted December 9, 2015 4:06 PM

• by ajamyajax

  Re 211525389 from Martti's list: had to use limited data for this fit, but looks like a nice sub-Neptune with an estimate of ~0.81+ R_sol for the star.

  s1=2306.745 p1=8.2623 d1=0.13 (3.12 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211525389 , 2MASS J08214087+1329512 , 10.541 , 10.173 , 10.091 , 0.368 , 0.082 , ('G9V', 0.91) , ('G9V', 0.91)

  au min-max 0.07 0.08
  
  stellar diameter in solar units min-max 0.72 0.875
  
  stellar mass in solar units min-max 0.67 1.0
  
  period in days min-max 8.26 8.265
  
  duration in hours min-max 3.025 3.217
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211525389 125.4203 13.4975 0.13 11.687 5
  

  

  Posted December 9, 2015 4:08 PM

• by ajamyajax

  Re 211886472 from Hans Martin's list: very spare EB-looking transits and a range of stellar estimates suggest a binary here (not shown).

  s1=2319.38 p1=19.644 d1=0.195 (4.68 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211886472 , 2MASS J09083180+1831428 , 10.235 , 9.980 , 9.975 , 0.255 , 0.005 , ('F9V', 1.14) , ('B9V', 2.8)

  au min-max 0.125 0.145
  
  stellar diameter in solar units min-max 0.82 0.99
  
  stellar mass in solar units min-max 0.675 1.055
  
  period in days min-max 19.634 19.647
  
  duration in hours min-max 4.587 4.771
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211886472 137.1325 18.5285 0.19 11.126 5
  
  211887665 137.1141 18.5463 89.69 18.102 5
  
  211885243 137.0992 18.5117 128.93 16.268 5
  

  Posted December 12, 2015 8:59 PM

• by ajamyajax

  Re 211818569 from Hans Martin's list: this one looks pretty good as a high-impact hot gas giant candidate. Should of course be observed for any sign of a binary companion though. 0.68X R_sol estimate for the star here.

  s1=2310.56 p1=5.186 d1=0.10 (2.4 hours or more)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211818569 , 2MASS J08274481+1734457 , 11.309 , 10.742 , 10.616 , 0.567 , 0.126 , ('K6V', 0.7) , ('K4V', 0.78)

  au min-max 0.05 0.055
  
  stellar diameter in solar units min-max 0.625 0.74
  
  stellar mass in solar units min-max 0.62 0.825
  
  period in days min-max 5.186 5.187
  
  duration in hours min-max 2.307 2.492
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211818569 126.9367 17.5794 0.07 12.935 5
  
  211817229 126.9730 17.5601 142.58 15.682 5
  

  

  Posted December 12, 2015 9:01 PM

• by ajamyajax

  Re 211808055 from Hans Martin's list: looks contaminated by a nearby EB (EPIC 211807843/J08360704+1725381).

  s1=2309.62 p1=3.3814 d1=0.15 (3.6 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211808055 , 2MASS J08360827+1725483 , 12.545 , 12.200 , 12.141 , 0.345 , 0.059 , ('G8V', 0.94) , ('F6V', 1.25)

  211807843 , 2MASS J08360704+1725381 , 10.565 , 10.325 , 10.299 , 0.24 , 0.026 , ('G0V', 1.09) , ('B9.5V', 2.5)

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211808055 129.0345 17.4301 0.15 13.741 5
  
  211807843 129.0293 17.4272 20.54 11.443 5
  

  From NEA, 2MASS Objects within search area:
  
  2MASS Designation RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] J [mag] V or R [mag] Photometric flags
  
  08360827+1725483 129.034498 17.430098 0.14 12.545 13.70 AAA
  
  08360704+1725381 129.029359 17.427250 20.27 10.565 11.38 AAA
  

  From VSX:

  Dist. ' Name AUID Coords (J2000) Const. Var. type Period (d) Mag. range

  0.34 Variable ASAS J083607+1725.6 -- 08 36 07.04 +17 25 38.1 Cnc ED 6.763575 11.38 (0.26) V

  http://www.aavso.org/vsx/index.php?view=detail.top&oid=87400

  

  Posted December 14, 2015 11:43 PM

• by ajamyajax

  Re 211817572 from Hans Martin's list: V-shaped transits with a drop of only ~0.5%, but a consistent secondary transit is visible (pictured). So this could still be a HJ, but combined with a range of stellar estimates perhaps a binary is more likely.

  s1=2307.017 p1=2.2598 d1=0.07 (1.68 hours +/-)

  s2=2308.15 p2=2.2598 d2=0.06 (1.44 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211817572 , 2MASS J08122305+1733545 , 10.489 , 10.272 , 10.183 , 0.217 , 0.089 , ('F7V', 1.21) , ('G9V', 0.91)

  au min-max 0.025 0.03
  
  stellar diameter in solar units min-max 0.49 0.665
  
  stellar mass in solar units min-max 0.405 0.71
  
  period in days min-max 2.252 2.269
  
  duration in hours min-max 1.582 1.777
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211817572 123.0961 17.5652 0.23 11.385 5
  
  211818106 123.0962 17.5730 28.25 12.961 5
  
  211816649 123.0581 17.5519 138.73 13.542 5
  

  

  Posted December 14, 2015 11:46 PM

• by ajamyajax

  Re 211816003 from Hans Martin's list: looks all right as a sub-Neptune planet candidate. 0.76X R_sol estimate.

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  s1=2311.863 p1=14.45 d1=0.15 (3.6 hours)

  211816003 , 2MASS J08502906+1732328 , 12.486 , 12.076 , 12.000 , 0.41 , 0.076 , ('K1V', 0.86) , ('G6V', 0.97)

  au min-max 0.105 0.11
  
  stellar diameter in solar units min-max 0.715 0.79
  
  stellar mass in solar units min-max 0.74 0.85
  
  period in days min-max 14.446 14.453
  
  duration in hours min-max 3.501 3.697
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211816003 132.6211 17.5424 0.18 13.654 5
  
  211818139 132.6377 17.5733 124.81 15.244 5
  
  211815826 132.6630 17.5399 144.05 14.743 5
  

  

  Posted December 14, 2015 11:47 PM

• by ajamyajax

  Re 211736671 from Hans Martin's list: fairly consistent transits make for a decent fit and another possible sub-Neptune planet candidate. The bright neighbor is 211737410, but its LC shows no sign of contaminating transits. 0.95X R_sol estimate.

  s1=2307.355 p1=4.735 d1=0.13 (3.12)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211736671 , 2MASS J08133165+1625107 , 10.986 , 10.652 , 10.561 , 0.334 , 0.091 , ('G6V', 0.97) , ('G9V', 0.91)

  211737410 , 2MASS J08132830+1625472 , 8.158 , 7.997 , 7.969 , 0.161 , 0.028 , ('F4V', 1.37) , ('B9.5V', 2.5)

  au min-max 0.05 0.06
  
  stellar diameter in solar units min-max 0.9 1.145
  
  stellar mass in solar units min-max 0.745 1.29
  
  period in days min-max 4.726 4.745
  
  duration in hours min-max 3.026 3.217
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211736671 123.3819 16.4196 0.09 12.160 5
  
  211737410 123.3679 16.4298 60.62 8.833 5
  

  
  

  Posted December 18, 2015 12:36 PM

• by ajamyajax

  Re 211733267 from Hans Martin's list: smooth LC and the fit looks stellar, but with gas giant depth there is some chance of a high-impact PC. 0.60x R_Sol estimate.

  s1=2311.934 p1=8.6576 d1=0.10 (2.4 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211733267 , 2MASS J08400226+1622206 , 10.841 , 10.407 , 10.287 , 0.434 , 0.12 , ('K3V', 0.81) , ('K3V', 0.81)

  au min-max 0.06 0.075
  
  stellar diameter in solar units min-max 0.45 0.605
  
  stellar mass in solar units min-max 0.385 0.75
  
  period in days min-max 8.651 8.663
  
  duration in hours min-max 2.309 2.489
  

  Semi-Major Axis a (A.U.) = 0.07694
  
  Stellar diameter ratio = 0.60
  
  Stellar mass ratio = 0.81
  
  Period ~= 8.66 days
  
  Duration ~= 2.4 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211733267 130.0094 16.3724 0.05 12.150 5
  
  211733485 130.0002 16.3754 33.60 13.012 5
  
  211731569 130.0234 16.3478 100.90 11.221 5
  
  211735220 129.9924 16.3996 114.18 14.322 5
  

  

  Posted December 18, 2015 12:38 PM

• by ajamyajax

  Re 211713099 from Hans Martin's list: a range of stellar parameters, but still looks good as a gas giant candidate. 0.97X R_sol estimate.

  s1=2308.15 p1=8.5628 d1=0.15 (3.6 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211713099 , 2MASS J08205372+1605274 , 12.555 , 12.203 , 12.154 , 0.352 , 0.049 , ('G8V', 0.94) , ('F1V', 1.5)

  au min-max 0.07 0.09
  
  stellar diameter in solar units min-max 0.805 1.09
  
  stellar mass in solar units min-max 0.625 1.325
  
  period in days min-max 8.556 8.572
  
  duration in hours min-max 3.502 3.698
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211713099 125.2239 16.0909 0.18 13.640 5
  
  211712822 125.2324 16.0872 32.41 19.089 5
  
  211712138 125.2182 16.0778 51.25 12.970 5
  
  211712370 125.2373 16.0811 58.41 14.737 5
  
  211711296 125.2111 16.0661 99.78 15.919 5
  
  211714642 125.2455 16.1123 107.24 14.293 5
  

  

  Posted December 18, 2015 12:39 PM

• by Dolorous_Edd

  EPIC 211929937

  UKIDSS K-band

  

  1'x1'

  CFHT R-band

  

  Log, greyscale

  Posted December 18, 2015 5:29 PM

• by Dolorous_Edd

  EPIC 212132195

  UKIDSS J-band

  1'x1'

  

  Posted December 18, 2015 5:41 PM

• by Dolorous_Edd

  EPIC 212099230

  UKIDSS K-band

  1'x1'

  

  Posted December 19, 2015 11:38 AM

• by JKD

  211929741 - PC at

  Signal ~2365.01 BKJD

  Duration ~7.355 hrs

  Signal Depth: ~2700 ppm

  Posted December 20, 2015 6:34 PM

• by ajamyajax

  Re 211579112 from Hans Martin's list: this target has a brightness of only 15.768 Kep Mag, but a possible mini gas giant if a small dwarf here. 0.32x R_sol estimate.

  s1=2323.42 p1=17.71 d1=0.0875 (2.1 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211579112 , 2MASS J09033200+1415018 , 13.501 , 12.947 , 12.638 , 0.554 , 0.309 , ('K4V', 0.78) , ('M4V', 0.24)

  au min-max 0.09 0.1
  
  stellar diameter in solar units min-max 0.29 0.345
  
  stellar mass in solar units min-max 0.31 0.425
  
  period in days min-max 17.702 17.717
  
  duration in hours min-max 2.023 2.189
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211579112 135.8833 14.2505 0.16 15.768 5
  
  211581282 135.8675 14.2824 127.36 13.473 5
  
  211578399 135.9243 14.2397 148.15 11.907 5
  

  

  Posted December 21, 2015 10:55 PM

• by Dolorous_Edd

  EPIC 212008766

  UKIDSS K-band

  1'x1'

  

  Posted December 23, 2015 5:55 PM

• by Dolorous_Edd

  EPIC 211923431

  UKIDSS K-band

  1'x1'

  

  Posted December 23, 2015 6:05 PM

• by Dolorous_Edd

  EPIC 211919004

  UKIDSS K-band

  1'x1'

  

  There is a star to the west ~1.5" , binary?

  CFHT I-band

  

  Posted December 25, 2015 7:21 PM

• by Dolorous_Edd

  EPIC 211916756

  UKIDSS K-band

  1'x1'

  

  CFHT G-band

  

  Posted December 25, 2015 7:26 PM

• by Dolorous_Edd

  EPIC 211818569

  CFHT R-band

  zoom-in / zoom-out

  

  Posted December 25, 2015 7:43 PM

• by Dolorous_Edd

  EPIC 211816003

  UKIDSS K-band

  1'x1'

  

  CFHT I-band

  zoom-in / zoom-out

  

  Posted December 26, 2015 8:14 PM

• by Dolorous_Edd

  EPIC 211733267

  CFHT R-band

  zoon-in / zoom-out

  

  Posted December 28, 2015 1:57 PM

• by zoo3hans

  Additional candidates from the C5_K2_Korr light curves (by courtesy of Andrew Vanderburg):

  (Dull glitch at BKJD 2334.9, smaller one at 2340.02, maybe another at 2353.15)

  EPIC 211305568 might have two transits at 2359.44, 2324.8, possible period 34.64 days.

  EPIC 211307956 Probably bad glitch at BKJD 2343.5, also for EPIC 211230123.

  EPIC 211311054 Very fast occuring dips, period about 0.147 days, depth only 0.0009. I assume contamination by a BGEB.

  EPIC 211311260 Maybe single transit at BKJD 2325.33.

  (As mentioned by Martti: EPIC 211311380 Obvious multiplanet system)

  EPIC 211315224 Maybe single transit at BKJD 2342.8.

  (As mentioned by Martti: EPIC 211319617 regular transits with period 8.868 days, U-shaped, no secondaries visible, to me it looks like a valid candidate)

  EPIC 211320412 Maybe single transit at BKJD 2352.7.

  EPIC 211328748 4 transits at BKJD 2324.13, 2341.29, 2358.47, 2375.65. Period about 17.17 days. Depth 0.00026. Duration about 4 hours.

  EPIC 211331236 Multiplanet candidate. One period 1.292 days. Starting at BKJD 2309.7037. Depth about 0.0015. Duration about 2 hours. Another object seems to have a period around 5.45 days. Similar depth. Duration about 3 hours. Starting at BKJD 2310.5137.

  EPIC 211335477 Maybe single transit at BKJD 2358.75.

  EPIC 211336073 Maybe transit at BKJD 2332.46.

  EPIC 211340040 Maybe transit at BKJD 2338.18.

  EPIC 211346584 Maybe transit at BKJD 2353.67.

  EPIC 211347012 Maybe grazing long transit at BKJD 2342.68, depth 0.0027, duration 8.5 hours.

  EPIC 211351543 Maybe single transit at BKJD 2373.79, depth 0.00044, duration about 5 hours.

  (As mentioned by Martti: EPIC 211351816 first transit at 2309.06, period 8.402 days, depth 0.0009, duration about 7 hours. There seem to be other transits present in the LC as well.)

  EPIC 211355342 Period 6.893 days, starting at BKJD 2310.8, depth 0.0008, duration about 3 hours, fairly U-shaped.

  EPIC 211356358 Maybe transit at BKJD 2352.7.

  (As mentioned by Martti: EPIC 211359660 P = 4.736 days, depth 0.0012, duration about 3.5-4.0 hours.)

  EPIC 211376702 Maybe transit at BKJD 2331.1.

  (As mentioned by Martti: EPIC 211390677 Very strange dip at 2318.8. Maybe a large ringed Jupiter-like planet? Depth 0.01, "ring"-depth 0.005. BUT according to Andrew Vanderburg it's a software issue (mentioned by ajamyajax in a private email).)

  (As mentioned by Martti: EPIC 211391664 Period about 10.138 days, depth 0.001, duration about 5.5 hours. Substructure visible in the transits, probably star spots -> maybe rotation period of star can be found.)

  EPIC 211392382 Maybe transit at 2343.52. Depth about 0.007.

  (As mentioned by Martti: EPIC 211399359 P = 3.115 days, depth 0.027, duration about 3 hours. Maybe Hot Jupiter.)

  EPIC 211401787 Period 13.77 days, starting at BKJD 2318.06, depth 0.0003, duration about 3.5 hours.

  EPIC 211406700 Maybe transit at BKJD 2342.75.

  EPIC 211407755 Period about 36.08 days, at BKJD 2327.24 and 2363.32, depth 0.004, duration about 3.5 hours.

  EPIC 211411112 Single transit at 2345.95, depth 0.026, rather V-shaped.

  EPIC 211413463 As Martti mentioned probably EB, but still a slight change for a grazing HJ, depth 0.03, period around 3.25175 days.

  EPIC 211413752 Period around 9.324 days, starting at 2307.84, depth 0.0006, duration about 4 hours.

  EPIC 211416496 Maybe transit at 2342.69.

  (As mentioned by Martti: EPIC 211418729 Period about 11.39 days, depth 0.0154, duration about 4.5 hours, U-shaped, looks like a fine warm Jupiter.)

  (As mentioned by Martti: EPIC 211432167 Period around 5.8175 days, starting at BKJD 2308.93, depth 0.0111, duration about 4.5 hours.)

  EPIC 211442297 from Martti's list: P=20.27 days, depth 0.017, U-shaped, probably a good planet candidate. Also mentioned by ajamyajax and JKD.

  EPIC 211468623 Maybe transit at BKJD 2352.35.

  (As mentioned by Martti: EPIC 211490999, P=9.842 days, see also comment by ajamyajax http://talk.planethunters.org/?_ga=1.110727493.1777704650.1398881647#/boards/BPH0000007/discussions/DPH00019on?page=6 )

  EPIC 211491044 Maybe transit at 2310.98 and 2360.86, depth 0.0004, duration about 6.5 hours, possible period around 49.88 days.

  EPIC 211496372 Maybe transit at BKJD 2335.75.

  EPIC 211496731 Maybe transit at 2317.82 and 2362.85, depth 0.0024, duration about 6.5 hours, possible period around 45.03 days.

  (As mentioned by Martti: EPIC 211503363 Obvious transit at BKJD 2364.52, depth 0.0039, duration about 0.93 days, nicely U-shaped. So this seems to be a good long period planet candidate.)

  EPIC 211503470 Maybe transit at BKJD 2353.13, depth 0.0003, duration about 3.5 hours, but probably contamination.

  EPIC 211505089 Period about 24.46 days, starting at BKJD 2313.93, depth 0.0007, duration about 6 hours.

  (As mentioned by Martti: EPIC 211509553 P=20.365 days, depth 0.036, U-shaped, a bit on the deep side, but might still be a valid PC (I see no secondaries).)

  EPIC 211518462 Maybe transit at BKJD 2352.4.

  (As mentioned by Martti: EPIC 211525389 Period around 8.266 days, starting at BKJD 2315.0, depth 0.0014, duration 4 hours.)

  EPIC 211529065 Period about 4.4 days, starting at BKJD 2309.97, depth 0.0013, duration about 3 hours.

  EPIC 211562654 Multiplanet system. One period about 10.794 days, starting at BKJD 2314.78, depth 0.0006, duration about 4 hours. The second planet has period 22.63 days, starting at BKJD 2311.14, depth 0.0009, duration about 5 hours. There is even a chance for a small third planet with period 4.249 days, especially visible around BKJD 2346.56 and 2350.78, depth 0.0005, duration about 3 hours.

  EPIC 211578235 Period about 11.007 days, starting at BKJD 2314.98, depth 0.0058, duration 2.5-3 days.

  EPIC 211579683 Period about 9.015 days, starting at BKJD 2311.6, depth 0.0008, duration about 4 hours.

  EPIC 211594205 Period about 16.99 days, starting at BKJD 2315.5, depth 0.00035, duration about 3 hours, U-shaped.

  EPIC 211598816 Single transit at BKJD 2363.35, depth 0.0097, duration about 3.5 hours.

  EPIC 211611158 Period about 52.71 days, starting at BKJD 2326.17, depth 0.0007, duration about 5.5 hours.

  EPIC 211633458 Single long transit at BKJD 2368.78, depth 0.001, duration about 11 hours, U-shaped.

  EPIC 211643038 Single transit or glitch at BKJD 2343.4, depth 0.004, duration about 0.9 days.

  EPIC 211680698 Period 50.92 days, starting at BKJD 2327.49, depth 0.0012, duration about 5 hours, U-shaped.

  EPIC 211719362 Period 0.20114 days, depth 0.004, duration about 2 hours.

  EPIC 211732823 Maybe long transit at BKJD 2311.3, depth 0.0007, duration 18 hours, another short one at BKJD 2365.2, depth 0.0007, duration about 2.5 hours.

  EPIC 211743521 Maybe single transit at BKJD 2342.66, depth 0.0006, duration about 5.5 hours.

  EPIC 211755473 Maybe period 26.24 days, starting at BKJD 2326.85, depth 0.0018, duration about 3.5 hours.

  EPIC 211765775 Period about 43.12 days, starting at BKJD 2329.42, depth 0.0006, duration about 7.5 hours. Other dips seem to be present as well.

  EPIC 211770795 (mentioned already on page 1), actually seems to be a multiplanet system. One planet with period 7.726 days, depth 0.0015, duration about 4 hours, starting at BKJD 2308.1, another planet maybe at BKJD 2316.2.

  EPIC 211775796 Maybe single transit at BKJD 2352.99, depth 0.001, duration 6.5 hours.

  EPIC 211791178 Period about 9.563 days, starting at BKJD 2313.91, depth 0.0008, duration about 3.5 hours.

  EPIC 211798340 Period 44.99 days, starting at BKJD 2311.06, depth 0.0002, duration about 7 hours.

  EPIC 211799258 Period 19.54 days, starting at BKJD 2320.13, depth 0.0652, duration only about 2 hours. Additional dips at BKJD 2340.65, 2342.56.

  EPIC 211804579 Period 1.5233 days, starting at 2308.2, depth 0.0005, duration about 4 hours.

  EPIC 211808943 EB, but additional dip at BKJD 2341.77, depth 0.002, duration 6 hours, "flanks" at BKJD 2349.4, antother transit event?

  EPIC 211817229 Period about 2.177 days, starting at BKJD 2307.69, depth 0.004, duration about 2 hours.

  EPIC 211822797 Period about 21.17 days, starting at BKJD 2311.41, depth 0.0015, duration about 4.5 hours.

  EPIC 211825799 Period about 33.24 days, starting at BKJD 2328.18, depth 0.0008, duration about 7 hours.

  EPIC 211827189 Maybe single transit at BKJD 2337.82, depth 0.0009, duration 6-7 hours..

  EPIC 211842983 Maybe single transit at BKJD 2322.3, depth 0.0004, duration about 24 hours.

  EPIC 211893543 Maybe period 29.25 days, starting at BKJD 2329.9, depth 0.0004, duration about 4.5 hours. Other dips as well.

  EPIC 211897901 Maybe single transit at BKJD 2348.63, depth 0.0011, duration about 6 hours.

  EPIC 211921217 Maybe single transit at BKJD 2352.97, depth 0.002, duration about 8.5 hours.

  EPIC 211923431 Period about 29.74 days, starting at BKJD 2310.82, depth 0.0008, duration 6 hours.

  EPIC 211938121 Maybe single transit at BKJD 2323.24, depth 0.0045, duration 8.5 hours.

  EPIC 211939692 Clearly a multiplanet system. Inredible system, if real: BKJD 2333.05 (depth 0.0005, 8.5h) , BKJD 2337.5 (depth 0.001, 10.5h) , BKJD 2341.0 (depth 0.00055, 8.5h) , BKJD 2358.9 (depth 0.0007, 13h) , BKJD 2359.9 (depth 0.00055, 8.5h) , 2380.5 (depth 0.00055, 8.5h).

  EPIC 211941362 Maybe single transit at BKJD 2353.16, depth 0.0025, duration 4.5 hours, but probably contamination.

  EPIC 211953574 Maybe single transit at BKJD 2360.59, depth 0.0005, duration 5.5 hours.

  EPIC 211980360 Period 5.388 days, starting at BKJD 2308.75, depth 0.025, duration 4.5 hours. Period could also be half this value, i.e. 2.694 days, or else contamination by a BGEB.

  EPIC 211988320 Multiplanet system, one period 63.85 days, starting at BKJD 2309.71, depth 0.002, duration 6 hours. Second period maybe 36.43 days, starting at BKJD 2329.2, depth 0.0015, duration 5 hours.

  EPIC 211991644 Maybe single transit at BKJD 2331.1, depth 0.0007, duration 13 hours.

  EPIC 212006318 Maybe single transit at BKJD 2351.4, depth 0.0003, duration 6.5 hours, other transits with period 14.46 days, starting at BKJD 2314.3, depth 0.0002, duration about 6 hours.

  EPIC 212006344 Period 2.22 days, starting at BKJD 2308.82, depth 0.0004, duration about 2 hours.

  EPIC 212009016 Maybe period 37.28 days, starting at BKJD 2331.68, depth 0.0006, duration about 4.5 hours.

  EPIC 212012119 Varoius dips, depth about 0.001, duration about 3 hours, one period 3.281 days, starting at BKJD 2309.138, depth 0.0013, duration 2.5 hours.

  EPIC 212026444 Maybe single transit at BKJD 2343.4 , depth 0.0007, duration 21 hours.

  EPIC 212030008 Maybe single transit at BKJD 2338.98, depth 0.003, duration about 8 hours.

  EPIC 212069861 Period 30.96 days, starting at BKJD 2314.49 , depth 0.002, duration about 4 hours.

  EPIC 212085656 Maybe period 50.63 days, starting at BKJD 2319.5, depth 0.03, duration only 2.5 hours, so this could be contamination though.

  EPIC 212091090 Maybe single transit at BKJD 2342.73 , depth 0.0007, duration 12.5 hours, rather V-shaped though. Maybe a smaller one at BKJD 2326.12 , depth 0.0003, duration about 8.5 hours.

  EPIC 212098979 Maybe transit at BKJD 2344.48, depth 0.0006, duration about 5.5 hours.

  EPIC 212130773 Period 18.715 days, starting at BKJD 2318.91, depth 0.002, duration about 7 hours.

  EPIC 212146642 Maybe single transits at BKJD 2342.73 , depth 0.0008, duration about 12 hours, at 2359.45, depth 0.003, duration about 3 hours.

  EPIC 212148549 Maybe single transits at BKJD 2312.31 , depth 0.0004, duration 6.5 hours.

  EPIC 212152341 Period 6.677 days, starting at BKJD 2308.3 , depth 0.06, duration about 2.5 hours. Maybe it's an EB instead since the depth is rather large.

  EPIC 212157262 Multiplanet system. One period 7.15 days, starting at BKJD 2313.32 , depth 0.0009, duration about 3.5 hours. Second period 13.61 days, starting at BKJD 2308.46, depth 0.0007 duration about 5 hours.

  My list is now complete here. I have merged this list with the one on page 1 of this thread. - Hans Martin Schwengeler aka zoo3hans

  Posted December 30, 2015 6:08 PM

• by ajamyajax

  Re 211311380 from Martti's list revisited: Yes MPC, and with more corrected data looks like two to four gas giants are possible here. Only one transit repeats which makes the other periods true estimates however. And the chances of glitches increase with these single events, too. It also concerns me that three possible longer-period transits appeared in the same short period window. And some could even be stars.. But all that considered, still an interesting candidate system.

  The star is designated 'BD+10 1799' per Simbad, an F8 star with proper motions of pm-ra/pm-dec -48.16 1.64 (mas/yr). And these calculations made with a star of 1.18x R_sol and 1.20x M_sol.

  s1=2319.275 p1=15.575 d1=0.21 (5.04 hours) ~2.42Re

  s2=2309.02 p2=235.9 d2=0.52 (12.48 hours) ~5.06Re

  s3=2333.31 p3=185.73 d3=0.48 (11.52 hours) ~3.84Re

  s4=2353.91 p4=796.5 d4=0.78 (18.72 hours) ~9.27Re

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211311380 , 2MASS J08262784+1004493 , 7.982 , 7.786 , 7.722 , 0.196 , 0.064 , ('F5V', 1.32) , ('F9V', 1.14)

  au min-max 0.12 0.145
  
  stellar diameter in solar units min-max 1.07 1.34
  
  stellar mass in solar units min-max 0.95 1.675
  
  period in days min-max 15.569 15.582
  
  duration in hours min-max 4.943 5.129
  

  Semi-Major Axis a (A.U.) = 0.1297
  
  Stellar diameter ratio = 1.18
  
  Stellar mass ratio = 1.2
  
  Period ~= 15.57 days
  
  Duration ~= 5.04 hours
  

  Semi-Major Axis a (A.U.) = 0.794
  
  Stellar diameter ratio = 1.18
  
  Stellar mass ratio = 1.2
  
  Period ~= 235.9 days
  
  Duration ~= 12.48 hours
  

  Semi-Major Axis a (A.U.) = 0.677
  
  Stellar diameter ratio = 1.18
  
  Stellar mass ratio = 1.2
  
  Period ~= 185.73 days
  
  Duration ~= 11.52 hours
  

  Semi-Major Axis a (A.U.) = 1.787
  
  Stellar diameter ratio = 1.18
  
  Stellar mass ratio = 1.2
  
  Period ~= 796.5 days
  
  Duration ~= 18.72 hours
  

  For Reference, a period of 796.5 days ~= 2.18 years
  
  Jupiter P=11.8 years, 5.20 AU
  
  Saturn P=29.5 years, 9.54 AU
  
  Neptune P=165 years, 30.06 AU
  

  
  
  
  
  

  Posted December 31, 2015 3:11 AM

• by ajamyajax

  All these K2 C5 targets appear to be contaminated by EB 211920612 to some degree. Also the primary could be a giant or subgiant.

  211920612: V* S Cnc -- Eclipsing binary of Algol type (detached) per Simbad; spectral type B9.5V+G8-9III-IV, proper motions mas/yr : -20.75 1.55

  Per VSX:

  Dist. ' Name AUID Coords (J2000) Const. Var. type Period (d) Mag. range

  0.00 Variable S Cnc 000-BCT-976 08 43 56.13 +19 02 03.0 Cnc EA/DS 9.4845516 8.29 - 10.25 V

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  

  211919528 130.9900 19.0182 61.13 13.286 5
  
  211920604 130.9625 19.0341 72.83 12.258 5
  
  211919680 131.0163 19.0202 121.19 16.863 5
  
  211922654 130.9465 19.0634 165.14 13.423 5
  
  211922804 130.9461 19.0656 171.31 14.564 5
  
  211922849 130.9364 19.0663 198.76 15.268 5
  
  211923502 130.9315 19.0759 233.15 13.055 5
  
  211919871 131.0518 19.0229 234.61 12.215 5
  
  211918985 131.0590 19.0097 270.35 16.401 5
  
  211915059 130.9747 18.9506 302.49 18.206 5
  
  211917204 131.0553 18.9835 303.86 14.381 5
  
  211915961 130.9315 18.9650 306.31 14.055 5
  
  211918605 130.8973 19.0039 314.25 15.607 5
  
  211914656 130.9532 18.9445 339.32 14.228 5
  
  211915413 131.0498 18.9558 360.44 17.933 5
  
  211913748 130.9599 18.9304 382.41 14.375 5
  
  211914381 131.0647 18.9403 435.72 17.807 5
  

  Posted January 2, 2016 10:52 PM

• by ajamyajax

  Re 211328748 from Hans Martin's list: seems like a blended binary with a V-shaped fit, but always a chance for a high-impact planet candidate at this transit depth. 1.0X R_sol estimate.

  s1=2324.13 p1=17.175 d1=0.18 (4.32 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211328748 , 2MASS J08405648+1025205 , 8.928 , 8.674 , 8.626 , 0.254 , 0.048 , ('F9V', 1.14) , ('F1V', 1.5)

  au min-max 0.14 0.14
  
  stellar diameter in solar units min-max 0.995 1.01
  
  stellar mass in solar units min-max 1.24 1.24
  
  period in days min-max 17.182 17.182
  
  duration in hours min-max 4.346 4.412
  

  Per NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211328748 130.2354 10.4224 0.08 9.947 5
  
  211328433 130.2665 10.4162 112.36 14.063 5
  
  211326602 130.2365 10.3820 145.41 16.505 5
  

  Note this star designated BD+10 1849 on Simbad: Spectral type G5, Proper motions mas/yr : -47.8 23.2

  

  Posted January 5, 2016 5:41 PM

• by ajamyajax

  Re 211331236 from Hans Martin's list: pretty good chance of two mini-gas giant planet candidates around a small M-dwarf star here (one PC fit shown). And there could be TTV but difficult to measure with sparse transit data. Edit: 0.67x R_sol estimate.

  s1=2308.475 p1=1.29192 d1=0.0625 (1.49 hours +/-)

  s2=2310.57 p2=5.4434 d2=0.10 (2.4 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211331236 , 2MASS J08552535+1028087 , 11.447 , 10.801 , 10.589 , 0.646 , 0.212 , ('M7V', 0.098) , ('M1V', 0.52)

  Semi-Major Axis a (A.U.) = 0.0207
  
  Stellar diameter ratio = 0.67
  
  Stellar mass ratio = 0.71
  
  Period ~= 1.29 days
  
  Duration ~= 1.49 hours
  

  Semi-Major Axis a (A.U.) = 0.054
  
  Stellar diameter ratio = 0.67
  
  Stellar mass ratio = 0.71
  
  Period ~= 5.44 days
  
  Duration ~= 2.4 hours
  

  Per NEA K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211331236 133.8557 10.4691 0.13 13.905 5
  
  211331917 133.8403 10.4817 70.80 14.311 5
  

  
  

  Posted January 5, 2016 5:42 PM

• by Dolorous_Edd in response to ajamyajax's comment.

  EPIC 211331236

  The Sky is clear

  UKIDSS J-band

  1'x1'

  

  Posted January 5, 2016 7:56 PM

• by Dolorous_Edd in response to ajamyajax's comment.

  EPIC 211328748 is SDSS J084056.47+102520.4

  

  There is a star nearby ~5" to the south

  SDSS J084056.69+102510.5

  

  Posted January 5, 2016 8:02 PM

• by ajamyajax

  Re 211763214 from Hans Martin's list: certainly a blended transit as you can see in this fit, but also a possible (and rare) near Earth radii PC if a star ~0.77x R_sol. Of course also a chance for a blended binary, or something else less exciting. But at least VSX and Simbad look ok.

  s1=2313.60 p1=21.18 d1=0.17 (4.09 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211763214 , 2MASS J08552113+1647389 , 11.291 , 10.911 , 10.796 , 0.38 , 0.115 , ('G9V', 0.91) , ('K3V', 0.81)

  Semi-Major Axis a (A.U.) = 0.1419
  
  Stellar diameter ratio = 0.77
  
  Stellar mass ratio = 0.85
  
  Period ~= 21.18 days
  
  Duration ~= 4.09 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211763214 133.8381 16.7942 0.13 12.529
  

  

  Posted January 10, 2016 4:54 PM

• by ajamyajax

  Re 211355342 from Hans Martin's list: possible TTV and blending so a small range for the stellar estimates here (maybe 0.83-1.00x R_sol). But a gas giant planet candidate is possible for all of this range. The upper estimate of 1.0 R_sol used for the fit.

  s1=2310.80 p1=6.8936 d1=0.13 (3.12 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211355342 , 2MASS J08301297+1054371 , 11.438 , 11.082 , 11.026 , 0.356 , 0.056 , ('G8V', 0.94) , ('F5V', 1.32)

  au min-max 0.06 0.075
  
  stellar diameter in solar units min-max 0.74 0.98
  
  stellar mass in solar units min-max 0.605 1.185
  
  period in days min-max 6.886 6.901
  
  duration in hours min-max 3.022 3.214
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211355342 127.5540 10.9103 0.12 12.637 5
  

  

  Posted January 13, 2016 11:20 PM

• by ajamyajax

  Re 211401787 from Hans Martin's list: TTV seems likely here since the fit is better when that data is used. And this could also be a mini-gas giant. Consistent stellar parameters also with a 1.03X R_sol estimate.

  The star is listed as BD+12 1842 on Simbad; Proper motions mas/yr : -21.3 -13.0, Spectral type: F5. A small visual companion can be seen on Aladin Lite.

  s1=2318.073 p1=13.782 d1=0.175 (4.2 hours)

  ttv1=[2318.073,2331.875,2345.645,2359.385,2373.155]

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211401787 , 2MASS J08273526+1140030 , 8.668 , 8.460 , 8.412 , 0.208 , 0.048 , ('F6V', 1.25) , ('F1V', 1.5)

  au min-max 0.11 0.12
  
  stellar diameter in solar units min-max 0.92 1.05
  
  stellar mass in solar units min-max 0.935 1.215
  
  period in days min-max 13.774 13.781
  
  duration in hours min-max 4.102 4.29
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211401787 126.8970 11.6675 0.18 9.709 5
  

  

  Posted January 13, 2016 11:22 PM

• by ajamyajax

  Re 211562654 from Hans Martin's list: this nice find is an interesting MPC with three possible planet candidates... Note the star seems to be a bit larger than the colors suggest. And one of the PCs appears to have a high-impact transit, while another is often blended and possibly eccentric. 1.05x R_sol / 1.2x M_sol estimate.

  s1=2314.785 p1=10.7934 d1=0.165 (3.96 hours)

  s2=2311.149 p2=22.634 d2=0.21 (5.04 hours)

  s3=2308.265 p3=4.251 d3=0.12125 (2.91 hours)

  ...

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211562654 , 2MASS J08200170+1401100 , 11.485 , 11.152 , 11.021 , 0.333 , 0.131 , ('G6V', 0.97) , ('K6V', 0.7)

  au min-max 0.09 0.105
  
  stellar diameter in solar units min-max 0.905 1.105
  
  stellar mass in solar units min-max 0.835 1.325
  
  period in days min-max 10.792 10.796
  
  duration in hours min-max 3.861 4.055
  

  au min-max 0.14 0.17
  
  stellar diameter in solar units min-max 0.82 1.03
  
  stellar mass in solar units min-max 0.715 1.28
  
  period in days min-max 22.62 22.632
  
  duration in hours min-max 4.703 4.89
  

  au min-max 0.045 0.055
  
  stellar diameter in solar units min-max 0.835 1.09
  
  stellar mass in solar units min-max 0.67 1.23
  
  period in days min-max 4.244 4.26
  
  duration in hours min-max 2.811 3.007
  

  Semi-Major Axis a (A.U.) = 0.1015
  
  Stellar diameter ratio = 1.05
  
  Stellar mass ratio = 1.2
  
  Period ~= 10.78 days
  
  Duration ~= 3.97 hours
  

  Semi-Major Axis a (A.U.) = 0.1664
  
  Stellar diameter ratio = 1.05
  
  Stellar mass ratio = 1.2
  
  Period ~= 22.63 days
  
  Duration ~= 5.08 hours
  

  Semi-Major Axis a (A.U.) = 0.0546
  
  Stellar diameter ratio = 1.05
  
  Stellar mass ratio = 1.2
  
  Period ~= 4.25 days
  
  Duration ~= 2.91 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211562654 125.0072 14.0195 0.20 12.754
  

  
  
  
  

  Note the P=4.251 object has a transit overlap at 2333.78 BKJD with a transit of greater depth, so this data removed from that particular fit.

  Posted January 13, 2016 11:30 PM

• by zoo3hans in response to ajamyajax's comment.

  Thanks again Mark for all your good work!

  Posted January 14, 2016 7:58 AM

• by ajamyajax in response to zoo3hans's comment.

  Thanks Hans Martin, but you are the best Planet Hunter this site has ever seen!

  Sincerely, Mark

  Posted January 15, 2016 7:15 PM

• by ajamyajax

  Re: 211594205 from Hans Martin's list: looks like another possible super-Earth planet candidate around a small K-dwarf. Stellar radius estimate fitted at 0.6x R_sol, but could be slightly larger based on the colors.

  The star is designated TYC 809-394-1 on Simbad, Proper motions mas/yr : 87.6 -13.1. Also note the speck just to the left of my label in the Aladin Lite image is a distant quasar (2MASS J08363340+1429219), only 99.15 arcsecs from this target also according to Simbad.

  s1=2315.50 p1=16.995 d1=0.125 (3.0 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211594205 , 2MASS J08363360+1427429 , 8.920 , 8.513 , 8.380 , 0.407 , 0.133 , ('K2V', 0.85) , ('K6V', 0.7)

  au min-max 0.105 0.11
  
  stellar diameter in solar units min-max 0.505 0.56
  
  stellar mass in solar units min-max 0.535 0.615
  
  period in days min-max 16.99 16.992
  
  duration in hours min-max 2.908 3.081
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211594205 129.1401 14.4619 0.13 10.680 5
  
  211596215 129.1392 14.4894 98.92 17.887 5
  

  
  

  https://en.wikipedia.org/wiki/Quasar

  Posted January 15, 2016 7:18 PM

• by ajamyajax

  Re 211407755 from Hans Martin's list: two possible transit events that seem to have a Neptune class planetary depth. However the fit appears stellar and this star is listed as Cl* NGC 2682 FBC 582 -- Star in Cluster on Simbad.. And there is a faint visual companion (Cl* NGC 2682 FBC 575 -- Star in Cluster) only 5.49 arcsecs away. ~0.62x R_sol estimate.

  s1=2327.24 p1=36.078 d1=0.17 (4.08 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211407755 , 2MASS J08491298+1145340 , 12.853 , 12.301 , 12.202 , 0.552 , 0.099 , ('K4V', 0.78) , ('K3V', 0.81)

  au min-max 0.195 0.195
  
  stellar diameter in solar units min-max 0.61 0.63
  
  stellar mass in solar units min-max 0.76 0.76
  
  period in days min-max 36.077 36.077
  
  duration in hours min-max 4.017 4.149
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211407755 132.3040 11.7593 0.12 14.573 5
  
  211408339 132.3164 11.7682 54.09 12.607 5
  

  

  Posted January 17, 2016 4:23 PM

• by ajamyajax

  Re 211798340 from Hans Martin's list: another possible small radius PC at 1.72Re -- with a nice planetary fit -- around a ~1.3x R_sol star (+/-). But there are also small visual companions as seen in Aladin Lite to consider for a blended EB in the light curve.

  By my rough calculation though, this object would be far too small to be a binary companion of this star (assuming it transits at the primary star's equator) because 8.7 percent of 109 Earths is ~9.483x Re. See links below. So if not glitches this one could be considered a planet candidate because of its transit depth and appearance.

  Per Simbad this star is designated BD+17 1904, Proper motions mas/yr : 6.2 10.6, Spectral type: F5.

  s1=2311.06 p1=44.987 d1=0.33 (7.92 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211798340 , 2MASS J08405948+1717357 , 8.865 , 8.664 , 8.668 , 0.201 , -0.004 , ('F6V', 1.25) , ('B8V', 3.4)

  au min-max 0.25 0.3
  
  stellar diameter in solar units min-max 1.225 1.5
  
  stellar mass in solar units min-max 1.03 1.78
  
  period in days min-max 44.984 44.986
  
  duration in hours min-max 7.845 8.006
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211798340 130.2479 17.2933 0.10 9.747 5
  
  211797688 130.2710 17.2837 86.61 10.989 5
  

  
  

  "All stars should be at least 8.7 percent as wide as our own sun..."

  "Size of Smallest Possible Star Pinned Down"

  by Mike Wall, Space.com Senior Writer

  http://www.space.com/21420-smallest-star-size-red-dwarf.html

  And our Sun is 109 Earths wide per this article:

  http://science.nationalgeographic.com/science/space/solar-system/sun-article/#

  Posted January 17, 2016 4:27 PM

• by ajamyajax

  Re 211529065 from Hans Martin's list: possible two planet MPC although the shorter period transit is often blended and could be variable activity, star spots, or K2 systematics. And with the V-shaped fit in the P=4.39x transit pictured, there is also a chance of a blended binary instead of a high-impact PC. Note there is a nearby visual companion on Aladin Lite. 0.67x R_sol estimate.

  s1=2309.98 p1=4.3999 d1=0.09 (2.16 hours)

  s2=2308.64 p2=2.315 d2=0.075 (1.8 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211529065 , 2MASS J08450398+1332594 , 11.968 , 11.462 , 11.368 , 0.506 , 0.094 , ('K3V', 0.81) , ('K0V', 0.89)
  
  211527014 , 2MASS J08450382+1331150 , 10.111 , 9.512 , 9.386 , 0.599 , 0.126 , ('K5V', 0.75) , ('K4V', 0.78)
  
  211526901 , 2MASS J08450515+1331081 , 13.234 , 12.697 , 12.462 , 0.537 , 0.235 , M , ('K3V', 0.81) , ('M3V', 0.4)

  au min-max 0.04 0.05
  
  stellar diameter in solar units min-max 0.53 0.72
  
  stellar mass in solar units min-max 0.44 0.865
  
  period in days min-max 4.391 4.405
  
  duration in hours min-max 2.067 2.258
  

  au min-max 0.03 0.03
  
  stellar diameter in solar units min-max 0.62 0.69
  
  stellar mass in solar units min-max 0.67 0.675
  
  period in days min-max 2.31 2.319
  
  duration in hours min-max 1.706 1.898
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211529065 131.2666 13.5498 0.12 13.431 5
  
  211527014 131.2659 13.5208 104.55 11.859 5 --> Simbad: 2MASS J08450382+1331150 -- High proper-motion Star
  
  211526901 131.2715 13.5189 112.67 16.304 5 --> Simbad: 2MASS J08450515+1331081 -- High proper-motion Star
  
  211527091 131.2971 13.5220 146.42 10.377 5
  
  211531569 131.2451 13.5850 147.27 17.326 5
  

  
  
  

  Posted January 18, 2016 3:52 PM

• by ajamyajax

  Re 211939692 from Hans Martin's list: and a fascinating find it is. Because if real, this could be another special F-type star and system.
  First some background, this star is listed as TYC 1395-2119-1 -- Star on Simbad, ICRS coord. (ep=J2000): 08 33 36.441 +19 19 12.89, Proper motions mas/yr: -1.7 -12.8, Kep Mag 11.75.

  Based on the colors I estimate this is an F7V star, ~1.21x R_sol/M_sol. But the (maybe) incredible part is there are six distinct transit-like events that are in a near 1:2:3 period ratio by my rough estimates. And four of them have the same duration, too. Let me quickly add that all the durations seen here are probably too long for repeats in the observed window of time -- if they are planets orbiting this star.

  So what is going on here? The most obvious answer is they are glitches from K2 systematics. Or they could be just variable star activity.. Or heavy star spotting.. Or even yet just a blend of three or four BGEB's. But let's exclude that for a moment and consider they could be part of a permanent three-ring system of larger objects with these transits all being planetary. Or perhaps they are a collection of late heavy bombardment type objects.. Granted that is less likely because of the transit depths observed. But worth mentioning is up close, the transit-like events are more ragged and irregular than those we usually see from a solid object in transit (see example line fit).

  So FWIW these are the mostly natural cause possibilities as I see it, from the likely to the more fantastic.

  Edit: a more remote possibility is a collision between two planets. It would probably have to be two large planets though to disperse fragments this size. Maybe a Jupiter and a Saturn.

  s1=2333.05 p1=100.57 d1=0.40 (9.6 hours) ~3.38Re

  s2=2337.50 p2=196.14 d2=0.50 (12.0 hours) ~3.6Re

  s3=2341.00 p3=100.57 d3=0.40 (9.6 hours) ~3.53Re

  s4=2358.90 p4=290.62 d4=0.57 (13.68 hours) ~3.36Re

  s5=2359.90 p5=100.57 d5=0.40 (9.6 hours) ~3.02Re

  s6=2380.52 p6=100.57 d6=0.40 (9.6 hours) ~3.23Re

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211939692 , 2MASS J08333645+1919128 , 10.872 , 10.665 , 10.601 , 0.207 , 0.064 , ('F6V', 1.25) , ('F9V', 1.14)

  Semi-Major Axis a (A.U.) = 0.451
  
  Stellar diameter ratio = 1.21
  
  Stellar mass ratio = 1.21
  
  Period ~= 100.57 days
  
  Duration ~= 9.6 hours
  

  Semi-Major Axis a (A.U.) = 0.704
  
  Stellar diameter ratio = 1.21
  
  Stellar mass ratio = 1.21
  
  Period ~= 196.14 days
  
  Duration ~= 12.0 hours
  

  Semi-Major Axis a (A.U.) = 0.915
  
  Stellar diameter ratio = 1.21
  
  Stellar mass ratio = 1.21
  
  Period ~= 290.62 days
  
  Duration ~= 13.68 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211939692 128.4018 19.3202 0.21 11.750 5
  

  

  

  

  Posted January 19, 2016 6:01 PM

• by JKD

  Re 211939692: checking PDCSAP_ FLUX and SAP_FLUX the signal at ~57173.49 MJD with a duration of ~0.36 d looks real.
  Another potential signal at ~57143.19 MJD is hard to detect in SAP_FLUX

  Posted January 19, 2016 6:53 PM

• by JKD

  211798340 PDCSAP-Flux and SAP_Flux are confirming at transit at 57143.39 MJD with a period of 44.99 days

  Posted January 20, 2016 8:58 PM

• by Dolorous_Edd

  EPIC 211798340

  Nearest star is ~10" away to the south

  UKIDSS 1'x1' K-band

  

  CFHT I-band

  

  Posted January 22, 2016 7:50 AM

• by Dolorous_Edd

  EPIC 211939692

  Worth to note that it was imaged by Subaru telescope

  UKIDSS K-band 1'x1' looks clean

  

  CFHT R-band doesn't look so clean

  

  Looking at SDSS, I can say that the objects most likely high redshift elliptical galaxies

  Blue circles are SDSS photometric objects

  

  EPIC 211939692 was also imaged by Subaru telescope

  

  Posted January 22, 2016 8:04 AM

• by ajamyajax

  Re 211988320 from Hans Martin's list: only two transit signals each, but still a decent two-planet candidate in my view. Fairly dim star listed as 14.12 Kep Mag. 0.68x R_sol estimate, maybe a bit smaller. I didn't see any bright stars in the nearby field which is good.

  s1=2309.72 p1=63.85 d1=0.225 (5.4 hours +/-)

  s2=2329.19 p2=36.43 d2=0.19 (4.56 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211988320 , 2MASS J09042119+2003557 , 12.208 , 11.517 , 11.360 , 0.691 , 0.157 , ('M8V', 0.082) , ('K6V', 0.7)

  au min-max 0.26 0.295
  
  stellar diameter in solar units min-max 0.61 0.71
  
  stellar mass in solar units min-max 0.575 0.84
  
  period in days min-max 63.853 63.858
  
  duration in hours min-max 5.316 5.47
  

  au min-max 0.195 0.195
  
  stellar diameter in solar units min-max 0.675 0.7
  
  stellar mass in solar units min-max 0.745 0.745
  
  period in days min-max 36.439 36.439
  
  duration in hours min-max 4.489 4.656
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211988320 136.0884 20.0655 0.18 14.122 5
  

  
  

  Posted January 22, 2016 3:30 PM

• by ajamyajax

  Re 211611158 from Hans Martin's list: another two-repeat transit (edit: should read two-event transit) that could be a mini-gas giant planet candidate. Note there are visual companions as seen on Aladin Lite, one of which is fairly bright. 0.79x R_sol estimate with an even larger mass.

  s1=2326.163 p1=52.713 d1=0.23 (5.52 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211611158 , 2MASS J08410232+1441250 , 11.066 , 10.749 , 10.680 , 0.317 , 0.069 , ('G5V', 0.98) , ('G2V', 1.0)

  au min-max 0.25 0.27
  
  stellar diameter in solar units min-max 0.725 0.805
  
  stellar mass in solar units min-max 0.75 0.945
  
  period in days min-max 52.713 52.719
  
  duration in hours min-max 5.42 5.594
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211611158 130.2597 14.6903 0.16 12.414 5
  

  
  

  Posted January 22, 2016 3:32 PM

• by ajamyajax

  Re 211680698 from Hans Martin's list: maybe a faint secondary transit here, so a chance of a bgeb. Stellar estimates vary also which tend to suggest a binary. Also a fairly busy neighborhood of bright stars can be seen on Aladin Lite (not shown). But many of which are the K2 targets listed below.

  s1=2327.48 p1=50.92 d1=0.21 (5.04 hours or more)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211680698 , 2MASS J08483045+1539216 , 12.259 , 11.768 , 11.654 , 0.491 , 0.114 , ('K3V', 0.81) , ('K3V', 0.81)

  au min-max 0.275 0.29
  
  stellar diameter in solar units min-max 0.86 1.045
  
  stellar mass in solar units min-max 1.07 1.255
  
  period in days min-max 50.917 50.921
  
  duration in hours min-max 5.668 6.53
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211680698 132.1269 15.6560 0.06 13.727 5
  
  211679034 132.1098 15.6330 101.77 13.891 5
  
  211682419 132.1078 15.6789 105.77 10.756 5
  
  211678332 132.1209 15.6226 121.96 11.676 5
  
  211682423 132.0927 15.6789 144.42 12.617 5
  

  

  Posted January 22, 2016 3:35 PM

• by JKD

  RE 211611158
  agree with a PC signal at 2326.14 BKJD with a duration of 5.88 hrs and a signal depth ~770 ppm.
  A repeat with p~52.7d is not visible in PDCSAP- and SAP-Flux

  Posted January 22, 2016 7:24 PM

• by Dolorous_Edd

  EPIC 211680698

  CFHT R-band

  

  There is a small star to the north ~6" away

  Posted January 23, 2016 1:22 PM

• by ajamyajax

  Re 212157262: from Hans Martin's list: two possible blended planet candidate transits and another interesting MPC. Maybe one of them looks high-impact and could have a larger radius than the estimate shown. A somewhat near 1:2 orbital resonance helps the PC cause. Also looks like a quiet nearby field of smallish neighbors on Aladin Lite. ~0.935x R_sol estimate, perhaps a bit less.

  s1=2313.32 p1=7.15 d1=0.14 (3.36 hours)

  s2=2308.453 p2=13.621 d2=0.173 (4.16 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212157262 , 2MASS J08500566+2311333 , 11.687 , 11.289 , 11.196 , 0.398 , 0.093 , ('K0V', 0.89) , ('K0V', 0.89)

  Semi-Major Axis a (A.U.) = 0.0709
  
  Stellar diameter ratio = 0.935
  
  Stellar mass ratio = 0.93
  
  Period ~= 7.15 days
  
  Duration ~= 3.36 hours
  

  Semi-Major Axis a (A.U.) = 0.109
  
  Stellar diameter ratio = 0.935
  
  Stellar mass ratio = 0.93
  
  Period ~= 13.63 days
  
  Duration ~= 4.16 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212157262 132.5236 23.1926 0.03 12.864 5, Proper Motion (RA) [mas/yr],Proper Motion (Dec) [mas/yr], -11.600±1.600,-26.000±1.800
  
  212158569 132.5097 23.2225 117.06 14.710 5, Proper Motion (RA) [mas/yr],Proper Motion (Dec) [mas/yr], -8.300±3.100,-28.300±3.400
  
  212155946 132.4939 23.1642 141.85 13.053 5, Proper Motion (RA) [mas/yr],Proper Motion (Dec) [mas/yr], -1.700±1.900,-3.600±2.200
  

  also from Simbad, 57.89 arcseconds distant:

  08 47 13.49 +23 23 27.9, SDSS J085008.55+231215.3 -- Low-mass star (M<1solMass), Proper motions mas/yr : -1.0 5.0, Spectral type: M2V

  
  
  

  Posted January 29, 2016 8:04 PM

• by ajamyajax

  Re 211755473 from Hans Martin's list: only three transit events here that are even more blended. And a bit of a range in the stellar estimates. So maybe a slightly better chance this one is a bgeb. Note that two of the nearby K2 targets appear to be galaxies per Simbad and a visual inspection on Aladin Lite. They are located at the bottom-center of this image.

  s1=2326.85 p1=26.24 d1=0.145 (3.48 hours)

  s2=2334.90 p2=? d2=0.22 (5.28 hours) -- this is a glitch area per Hans Martin

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211755473 , 2MASS J08204726+1641029 , 13.141 , 12.574 , 12.331 , 0.567 , 0.243 , ('K6V', 0.7) , ('M2V', 0.5)

  211754662 , 2MASS J08204382+1640231 , 10.032 , 9.782 , 9.720 , 0.25 , 0.062 , ('F9V', 1.14) , ('F8V', 1.18)

  211753082 , 2MASS J08204985+1639041 , 14.968 , 14.354 , 13.935 , 0.614 , 0.419 , ('K6V', 0.7) , ('M7V', 0.098)

  au min-max 0.12 0.12
  
  stellar diameter in solar units min-max 0.435 0.445
  
  stellar mass in solar units min-max 0.335 0.335
  
  period in days min-max 26.232 26.232
  
  duration in hours min-max 3.385 3.462
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211755473 125.1970 16.6841 0.12 15.232 5, Proper Motion (RA) [mas/yr],Proper Motion (Dec) [mas/yr], -3.000±6.300,-78.400±6.900
  
  211754772 125.2085 16.6747 52.21 13.706 5, Proper Motion (RA) [mas/yr],Proper Motion (Dec) [mas/yr], 2.300±4.600,-5.200±5.000
  
  211754662 125.1826 16.6731 63.42 10.965 5, from Simbad: BD+17 1822 -- Star, Proper motions mas/yr: 18.0 -27.7, Spectral type: G5
  
  211753082 125.2077 16.6512 124.07 15.430 5, from Simbad: MCG+03-22-003 -- Active Galaxy Nucleus, 08 20 49.850 +16 39 03.82
  
  211752690 125.1920 16.6458 138.92 14.875 5, from Simbad: UGC 4350 -- Active Galaxy Nucleus, 08 20 46.093 +16 38 44.82
  

  
  

  Posted January 29, 2016 8:08 PM

• by JKD

  212141391 - PC

  Transit at ~2319.52 BKJD

  Period ~46.22 d

  Transit Duration ~1.96 hrs

  Posted January 29, 2016 9:11 PM

• by ajamyajax in response to JKD's comment.

  Re 212141391 from JKD: listed on NEA as Object Type EXTENDED, so this K2 target may not be stellar. Very faint at 18.231 Kep Mag. I assume there is something interesting here to someone though.

  s1=2319.525 p1=? d1=0.08 (1.92 hours)

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212141391 126.0559 22.8498 0.06 18.231 5
  
  212140084 126.0259 22.8231 138.32 14.639 5
  
  212140139 126.0880 22.8243 140.59 14.132 5
  
  212140453 126.0941 22.8302 145.05 13.812 5
  

  Posted January 30, 2016 4:57 PM

• by ajamyajax

  Re 211791178 from Hans Martin's list: also somewhat blended, but appears to have solid planetary characteristics and consistent stellar estimates. The neighborhood looks fairly quiet in Aladin Lite also (not pictured). Note Infra-Red source from Simbad listed with NEA data. 0.74x R_sol estimate.

  s1=2313.91 p1=9.564 d1=0.13 (3.12 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211791178 , 2MASS J08483431+1711267 , 12.000 , 11.471 , 11.388 , 0.529 , 0.083 , ('K3V', 0.81) , ('G8V', 0.94)

  au min-max 0.07 0.085
  
  stellar diameter in solar units min-max 0.625 0.8
  
  stellar mass in solar units min-max 0.5 0.895
  
  period in days min-max 9.566 9.568
  
  duration in hours min-max 3.025 3.21
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211791178 132.1430 17.1907 0.07 13.648, Simbad: 2MASS J08483431+1711267 -- Infra-Red source
  

  Proper Motion (RA) [mas/yr],Proper Motion (Dec) [mas/yr],-28.200±4.200,-26.200±4.300

  

  Posted January 30, 2016 4:58 PM

• by JKD

  212130773 - already commented by zoo3hans on page 1 and 10

  4 repeats with p~18.706 d starting at 2318.9 BKJD, transit duration ~6.68 hrs

  Posted January 30, 2016 8:26 PM

• by Dolorous_Edd in response to ajamyajax's comment.

  Re EPIC 211791178

  also somewhat blended

  IMO it is a blend

  CFHT I-band image (same image just different color scaling )

  Object looks extended, so there is very close star to the north

  In the UKIDSS image object looks extended too

  

  Posted January 30, 2016 8:55 PM

• by ajamyajax in response to Dolorous_Edd's comment.

  Thanks Ivan, couldn't see any of that on Aladin Lite. I wish we could (at least) tell how bright that close companion is, because it looks 60-70% visible.

  Posted January 30, 2016 11:31 PM

• by Dolorous_Edd in response to ajamyajax's comment.

  EPIC 211791178

  In one way you can

  UKIDSS K-band close up image

  

  They have magnitudes in UKIDSS catalog

  EPIC 211791178 is UGCS J084834.30+171126.5

  Companion is UGCS J084834.28+171127.9

  Posted January 31, 2016 10:48 AM

• by ajamyajax in response to Dolorous_Edd's comment.

  Neat. Will need to look into that more when I get the chance. Noticed there is a python interface for UKIRT too. So always more fascinating stuff to look into, as usual. 😃

  http://astroquery.readthedocs.org/en/latest/ukidss/ukidss.html

  Posted January 31, 2016 2:48 PM

• by ajamyajax

  Re 211799258 from Hans Martin's list: sparse transit data but an interesting and maybe a really small dwarf.. It could have either a high impact Saturn-size plus gas giant, or a very small stellar companion if not grazing as well. And if not possible contamination; did not check UKIRT yet.

  But appears to be a quiet neighborhood of similar dim stars at least (not shown). 0.32x R_sol estimate and 15.979 KepMag. This could be a flaring star as well if increases in flux are not asteroids nor glitches.

  s1=2320.147 p1=19.534 d1=0.09 (2.16 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211799258 , 2MASS J08325907+1718235 , 13.017 , 12.420 , 12.185 , 0.597 , 0.235 , ('K5V', 0.75) , ('M3V', 0.4)

  au min-max 0.09 0.105
  
  stellar diameter in solar units min-max 0.27 0.34
  
  stellar mass in solar units min-max 0.255 0.405
  
  period in days min-max 19.526 19.529
  
  duration in hours min-max 2.085 2.251
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211799258 128.2462 17.3065 0.23 15.979 5
  

  From Simbad: 2MASS J08325907+1718235 -- Star, Proper motions mas/yr : -33.9 -2.7, Spectral type: M2

  

  Posted January 31, 2016 2:52 PM

• by ajamyajax

  Re 211804579 from Hans Martin's list: this star looks like another nice giant or subgiant by my estimates. The Aladin Lite image here shows there is a close visual companion that needs to be resolved however. But a grazing PC still possible. 11.222 KepMag.

  s1=2308.2 p1=1.5235 d1=0.21 (5.04 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211804579 , 2MASS J08361626+1722539 , 10.255 , 9.928 , 9.861 , 0.327 , 0.067 , ('G6V', 0.97) , ('G0V', 1.09)

  (Note the NEA 2MASS value needs corrected; used Simbad value below J083616266+17225398)

  Semi-Major Axis a (A.U.) = 0.02637
  
  Stellar diameter ratio = 2.445
  
  Stellar mass ratio = 1.05
  
  Period ~= 1.53 days
  
  Duration ~= 5.04 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211804579 129.0678 17.3817 0.16 11.222 5
  
  211802972 129.0734 17.3587 84.89 16.673 5
  
  211802616 129.0483 17.3533 122.07 14.723 5
  
  211802147 129.0657 17.3469 125.34 14.391 5
  

  Listed as TYC 1392-2492-1 -- Star on Simbad, 08 36 16.266 +17 22 53.98, Proper motions mas/yr : -31.9 -7.9

  
  

  Posted January 31, 2016 2:55 PM

• by Dolorous_Edd

  Noticed there is a python interface for UKIRT too

  Yeah, soon I will become extinct like a dinosaur .. great news , sign

  EPIC 211799258

  Not all that great, in the CFHT images (both G-band (left ) and R-band (right ) a companion can be seen roughly ~2.2" away to the SW

  Strangely not visible in the UKIDSS image

  

  EPIC 211799258 is SDSS J083259.05+171823.3 looks like M type star

  

  Companion is SDSS J083258.80+171818.4

  

  Posted January 31, 2016 4:00 PM

• by ajamyajax in response to Dolorous_Edd's comment.

  Not to worry, you can do all the UKIRT and SDSS work here if you like. I am plenty busy with the stuff I do, as I am sure HM is and others when they have time. And C6 is almost here also (hopefully anyway). Also excellent images from you too, as always. Thank you!

  Posted January 31, 2016 7:10 PM

• by zoo3hans

  Dear Mark and DE

  I appreciate very much your good work here. Yes, I'm awaiting the new C6 data, I think I cannot pull out much more of the C5 data. On the other hand the normal PH classify page is rather annoying nowadays with all its dull simulations, I think - I hate it. And you cannot even zoom the Y-axis, although we have critisized this for years. Oh boy, sometimes our nerves are streched more than neccessary.

  Anyway, good luck to all of You! Cheers, Hans Martin

  Posted January 31, 2016 8:22 PM

• by ajamyajax

  Re: 211817229 from Hans Martin's list: this short period candidate is very blended, but not surprising since a small star and the stellar neighborhood is fairly busy with brighter stars. And it sure looks like a dim red dwarf from the DSS color image on Aladin Lite too. So a tough one to be confident about a PC. But an alternating fit did not show any obvious signs of a bgeb. 0.56x R_sol estimate.

  Note it is listed as LP 425-186 -- High proper-motion Star on Simbad, 08 27 53.51 +17 33 36.5, Proper motions mas/yr : -12 -380.

  s1=2307.695 p1=2.177 d1=0.065 (1.56 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211817229 , 2MASS J08275351+1733365 , 12.471 , 11.969 , 11.699 , 0.502 , 0.27 , ('K3V', 0.81) , ('M3V', 0.4)

  au min-max 0.025 0.03
  
  stellar diameter in solar units min-max 0.475 0.64
  
  stellar mass in solar units min-max 0.44 0.765
  
  period in days min-max 2.17 2.184
  
  duration in hours min-max 1.472 1.658
  

  Note EPIC and PC candidate 211818569 also near at 142.49 arcseconds away, but both ephemeris are different enough that contamination from a third source seems unlikely. 211818569's s1=2310.56 p1=5.186 d1=0.10 (2.4 hours or more)

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211817229 126.9730 17.5601 0.18 15.682 5
  
  211818569 126.9367 17.5794 142.49 12.935 5
  

  

  Posted February 2, 2016 12:55 PM

• by ajamyajax

  Re 211822797 from Hans Martin's list: a fairly convincing fit here for a mini gas giant planet candidate orbiting a dim red dwarf star. 0.63X R_sol estimate.

  s1=2311.41 p1=21.17 d1=0.153 (3.68 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211822797 , 2MASS J08413848+1738240 , 12.277 , 11.605 , 11.429 , 0.672 , 0.176 , ('M7V', 0.098) , ('K7V', 0.64)

  Semi-Major Axis a (A.U.) = 0.129
  
  Stellar diameter ratio = 0.63
  
  Stellar mass ratio = 0.639
  
  Period ~= 21.17 days
  
  Duration ~= 3.68 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211822797 130.4104 17.6400 0.12 14.568 5
  
  211821049 130.3948 17.6160 101.59 15.340 5
  

  Listed as Cl* NGC 2632 HSHJ 385 -- Star in Cluster on Simbad, Proper motions mas/yr : -32.6 -6.0, Spectral type: M0

  

  Posted February 2, 2016 12:57 PM

• by Dolorous_Edd

  EPIC 211817229

  Doesn't look that bad, nearest star is ~9" and brighter stars are min ~30" away

  CFHT R-band image

  

  In SDSS looks like M type star

  SDSS J082753.50+173333.9

  

  Posted February 2, 2016 2:29 PM

• by Dolorous_Edd

  EPIC 211822797

  Was imaged by the Subaru telescope

  

  Nearby close star is seen to the SE

  UKIDSS K-band 1'x1'

  

  Posted February 2, 2016 2:36 PM

• by ajamyajax

  Re 211924657 from Hans Martin's list: sparse and often blended transit events with TTV possible, but a chance for a hot Neptune with a possible gas or debris trail. 0.65x R_sol estimate.

  s1=2309.001 p1=2.64409 d1=0.08 (1.92 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211924657 , 2MASS J08400641+1905346 , 12.183 , 11.605 , 11.370 , 0.578 , 0.235 , ('K5V', 0.75) , ('M3V', 0.4)

  au min-max 0.03 0.035
  
  stellar diameter in solar units min-max 0.585 0.75
  
  stellar mass in solar units min-max 0.515 0.82
  
  period in days min-max 2.641 2.649
  
  duration in hours min-max 1.826 2.014
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211924657 130.0268 19.0929 0.11 15.031 5
  

  Also per Simbad 116.02 asecs distant: [BBG2010] 919 -- Brown Dwarf Candidate, J0840021+190356

  

  Posted February 4, 2016 12:46 PM

• by ajamyajax

  Re 211970234 from Hans Martin's list: small dim dwarf at 16.122 KepMag with either a grazing PC or a very blended binary. The stellar neighborhood is very busy also, with maybe even a galaxy visually nearby (not pictured). 0.54x R_Sol estimate.

  s1=2307.40 p1=1.4837 d1=0.06 (1.44 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211970234 , 2MASS J09042104+1946489 , 13.851 , 13.186 , 12.987 , 0.665 , 0.199 , ('M7V', 0.098) , ('K9V', 0.6)

  au min-max 0.02 0.02
  
  stellar diameter in solar units min-max 0.505 0.585
  
  stellar mass in solar units min-max 0.48 0.49
  
  period in days min-max 1.476 1.491
  
  duration in hours min-max 1.34 1.539
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211970234 136.0877 19.7803 0.12 16.122 5
  

  

  Posted February 4, 2016 12:48 PM

• by ajamyajax

  Re 211979325 from Hans Martin's list: this does appear to be binary, maybe even with a giant or subgiant. As HM mentioned perhaps a white dwarf companion is also possible. So hopefully more work can be done on this system.

  s1=2306.97 p1=1.03845 d1=0.15 (3.6 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211979325 , 2MASS J08354764+1955184 , 11.793 , 11.351 , 11.261 , 0.442 , 0.09 , ('K3V', 0.81) , ('G9V', 0.91)

  au min-max 0.025 0.03
  
  stellar diameter in solar units min-max 2.35 3.03
  
  stellar mass in solar units min-max 1.9 3.405
  
  period in days min-max 1.029 1.048
  
  duration in hours min-max 3.5 3.7
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211979325 128.9485 19.9217 0.18 13.180 5
  

  

  Posted February 4, 2016 12:49 PM

• by ajamyajax

  Re 211980360 from Hans Martin's list: this object is type extended. However the periodic transits in this LC still appear to be contamination from bright EB 211982753 three arcminutes away.

  EB 211982753:

  s1=2308.736 p1=5.3899 d1=0.27 (6.48 hours)

  s2=2311.43 p2=5.3899 d2=0.27 (6.48 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211982753 , 2MASS J08190007+1958335 , 8.236 , 8.180 , 8.154 , 0.056 , 0.026 , ('A7V', 1.76) , ('B9.5V', 2.5)

  From VSX:

  Dist. ' Name AUID Coords (J2000) Const. Var. type Period (d) Mag. range

  3.00 Variable ASAS J081900+1958.5 -- 08 19 00.08 +19 58 33.6 Cnc ED 5.3899 8.8 (0.17) V

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211980360 124.7153 19.9383 0.23 17.899 5
  
  211979026 124.7323 19.9172 95.33 14.911 5
  
  211980451 124.6806 19.9400 117.73 13.094 5, Simbad: 2MASS J08184335+1956240 -- Infra-Red source
  
  211982753 124.7503 19.9760 179.90 8.781 5, Simbad: HD 69735 -- Star, 08 19 00.0759 +19 58 33.575, Spectral type: A3
  

  Note EPIC's 211977364 and 211980815 also show faint contamination from this source.

  Posted February 5, 2016 4:07 PM

• by ajamyajax

  Re 212006344 from Hans Martin's list: more speculative, but maybe a high impact super-Earth with an additional PC transit here. The second possible event for the longer transit appears to be in glitch area, where it theoretically should be anyway. Aladin Lite does shown some nearby visual stars. 0.58X R_sol estimate. Edit: 2340.x could also be a glitch.

  s1=2308.82 p1=2.22 d1=0.07 (1.68 hours)
  s2=2340.02 p2=26.79 d2=0.16 (3.84 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212006344 , 2MASS J08255432+2021344 , 10.104 , 9.457 , 9.275 , 0.647 , 0.182 , ('M7V', 0.098) , ('K9V', 0.6)

  au min-max 0.025 0.03
  
  stellar diameter in solar units min-max 0.5 0.675
  
  stellar mass in solar units min-max 0.42 0.735
  
  period in days min-max 2.214 2.229
  
  duration in hours min-max 1.581 1.779
  

  Semi-Major Axis a (A.U.) = 0.144
  
  Stellar diameter ratio = 0.58
  
  Stellar mass ratio = 0.555
  
  Period ~= 26.79 days
  
  Duration ~= 3.84 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212006344 126.4763 20.3596 0.12 12.466 5
  
  212006673 126.4748 20.3649 19.86 14.409 5
  
  212005686 126.4948 20.3492 72.72 12.000 5
  

  
  

  Posted February 5, 2016 6:56 PM

• by ajamyajax

  Re 212012119 from Hans Martin's list: a nice smooth LC here reveals two periodic transits that could be PCs.. However several very close visual companions can be seen on Aladin Lite. 0.77x R_sol estimate.

  s1=2309.138 p1=3.2805 d1=0.093 (2.23 hours)

  s2=2309.49 p2=8.438 d2=0.1275 (3.06 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212012119 , 2MASS J08484077+2027182 , 10.364 , 9.861 , 9.749 , 0.503 , 0.112 , ('K3V', 0.81) , ('K3V', 0.81)

  Semi-Major Axis a (A.U.) = 0.04
  
  Stellar diameter ratio = 0.77
  
  Stellar mass ratio = 0.807
  
  Period ~= 3.28 days
  
  Duration ~= 2.23 hours
  

  Semi-Major Axis a (A.U.) = 0.076
  
  Stellar diameter ratio = 0.77
  
  Stellar mass ratio = 0.807
  
  Period ~= 8.43 days
  
  Duration ~= 3.06 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212012119 132.1699 20.4551 0.09 11.753 5
  
  212011394 132.2083 20.4433 136.31 15.206 5, Simbad: 2MASS J08484997+2026359 -- Low-mass star (M<1solMass), Spectral type: M1
  

  
  
  
  

  Posted February 6, 2016 2:24 PM

• by ajamyajax

  Re 212069861 from Hans Martin's list: only three transit events, but a possible mini gas giant planet candidate orbiting a small dwarf. 0.48x R_sol estimate.

  s1=2314.49 p1=30.96 d1=0.14 (3.36 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212069861 , 2MASS J08574660+2127127 , 11.907 , 11.250 , 11.055 , 0.657 , 0.195 , ('M7V', 0.098) , ('K8V', 0.62)

  au min-max 0.15 0.165
  
  stellar diameter in solar units min-max 0.445 0.515
  
  stellar mass in solar units min-max 0.47 0.625
  
  period in days min-max 30.951 30.965
  
  duration in hours min-max 3.268 3.452
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212069861 134.4442 21.4535 0.12 14.102 5
  
  212069268 134.4467 21.4420 42.36 13.753 5
  
  212068112 134.4519 21.4213 118.88 13.628 5
  
  212068149 134.4280 21.4223 124.84 15.411 5
  

  

  Posted February 6, 2016 4:32 PM

• by ajamyajax

  Re 212130773 from Hans Martin's list and JKD's mention: I get a wide range of stellar estimates here, so my guess is this is a blended binary system. Another possibility is a late main sequence star or something a little more unusual like that. And a PC is still possible also.

  s1=2318.89 p1=18.71 d1=0.25 (6.0 hours or more)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212130773 , 2MASS J08234865+2238024 , 12.871 , 12.388 , 12.260 , 0.483 , 0.128 , ('K2V', 0.85) , ('K4V', 0.78)

  au min-max 0.14 0.16
  
  stellar diameter in solar units min-max 1.24 1.465
  
  stellar mass in solar units min-max 1.045 1.56
  
  period in days min-max 18.704 18.719
  
  duration in hours min-max 5.9 6.099
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212130773 125.9528 22.6340 0.18 14.467 5
  

  

  Posted February 6, 2016 4:33 PM

• by Dolorous_Edd

  And thanks to you for your plots and input, Mark!

  EPIC 211924657

  UKIDSS K-band image ( well, part of it )

  

  There is a star to the NW ~4" away

  Subaru telescope image

  

  Posted February 9, 2016 6:28 AM

• by Dolorous_Edd

  EPIC 211970234

  Only SDSS, purely to look at it

  Indeed looks like M type star

  

  SDSS J090421.05+194648.7 - 1237667252922286179

  Posted February 9, 2016 6:56 AM

• by Dolorous_Edd

  EPIC 211979325

  Doesn't look all that bad, there is a star but it is ~11,5" away to the SE

  UKIDSS K-band 1'x1'

  

  CFHT G-band

  

  Posted February 9, 2016 7:03 AM

• by Dolorous_Edd

  EPIC 212130773

  Looks good, more or less

  UKIDSS J-band

  1'x1'

  

  Posted February 9, 2016 7:20 AM

• by Dolorous_Edd

  EPIC 212069861

  Doesn't look like M type star IMO

  

  SDSS J085746.59+212712.4 - 1237667255606313046

  Posted February 9, 2016 7:26 AM

• by ajamyajax in response to Dolorous_Edd's comment.

  Re 212069861's M-type: well it looks orange-red when SDSS9 colored on Aladin Lite, so maybe it just appears brighter in your image because it is closer? Just a guess of course.

  From NEA, Proper Motion (RA) [mas/yr],Proper Motion (Dec) [mas/yr]:

  -13.200±4.700,-59.600±5.000

  

  Posted February 9, 2016 2:55 PM

• by ajamyajax in response to ajamyajax's comment.

  Check out the SDSS9 colored image of 212012119 on Aladin Lite:

  

  Posted February 9, 2016 3:00 PM

• by Dolorous_Edd in response to ajamyajax's comment.

  EPIC 212069861

  brighter in your image because it is closer?

  Nope, it is because my images directly from SDSS server

  Aladin compress images, so in the end they look crappier ( they are blurred horribly )

  Posted February 9, 2016 5:20 PM

• by ajamyajax

  p.s. also will be catching up on closer looks for a few remaining C5 LCs with periodic transits here: Those that are either likely to be stellar or are difficult to determine.. Just in case it helps:

  ---

  Re 211987231 from Hans Martin's list: with a V-shaped 2.1% dip and a wide range of stellar estimates, looks like a binary here.

  s1=2308.818 p1=17.0315 d1=0.12 (2.88 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211987231 , 2MASS J09093189+2002538 , 10.723 , 10.389 , 10.340 , 0.334 , 0.049 , ('G6V', 0.97) , ('F1V', 1.5)

  au min-max 0.09 0.1
  
  stellar diameter in solar units min-max 0.415 0.49
  
  stellar mass in solar units min-max 0.335 0.46
  
  period in days min-max 17.03 17.038
  
  duration in hours min-max 2.788 2.97
  

  And from NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211987231 137.3830 20.0482 0.17 11.680 5
  
  211987662 137.3825 20.0549 24.01 16.488 5
  
  211987940 137.4164 20.0596 120.16 16.165 5
  

  SIMBAD: TYC 1407-12-1, Proper motions mas/yr : -18.0 -1.8

  

  Posted February 10, 2016 2:48 PM

• by ajamyajax

  Re 212154564 from Hans Martin's list: not a great fit due to picket fence look but a possible blended high impact PC transit with a small dwarf. 0.43x R_sol estimate.

  s1=2309.165 p1=6.4156 d1=0.08 (1.92 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212154564 , 2MASS J08543387+2307584 , 12.838 , 12.227 , 11.975 , 0.611 , 0.252 , ('K6V', 0.7) , ('M4V', 0.24)

  au min-max 0.045 0.055
  
  stellar diameter in solar units min-max 0.36 0.485
  
  stellar mass in solar units min-max 0.295 0.54
  
  period in days min-max 6.411 6.419
  
  duration in hours min-max 1.825 2.012
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212154564 133.6412 23.1329 0.07 15.105 5
  
  212154828 133.6226 23.1388 65.09 15.100 5
  

  

  Posted February 10, 2016 2:52 PM

• by ajamyajax

  Re 212165050 from Hans Martin's list: this one looks like a periodic variable, but a binary or PC still possible with five transit events that seem very close to this period (periodic variables are often just close).

  s1=2313.38 p1=16.80 d1=0.55 (13.2 hours +/-)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212165050 , 2MASS J08445883+2322167 , 10.321 , 10.275 , 10.216 , 0.046 , 0.059 , ('A5V', 1.9) , ('F6V', 1.25)

  From K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212165050 131.2451 23.3713 0.05 10.736 5
  
  212165920 131.2608 23.3910 87.92 16.633 5
  
  212164666 131.2129 23.3622 111.30 11.435 5
  
  212166101 131.2167 23.3954 127.81 12.215 5
  

  

  Posted February 10, 2016 5:33 PM

• by ajamyajax

  Re 212138198 from Hans Martin's list: a blended or grazing transit here that could be either a high-impact PC or a small binary star.

  s1=2309.38 p1=3.2085 d1=0.06 (1.44 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212138198 , 2MASS J08240565+2246598 , 11.456 , 10.990 , 10.880 , 0.466 , 0.11 , ('K2V', 0.85) , ('K2V', 0.85)

  au min-max 0.03 0.035
  
  stellar diameter in solar units min-max 0.355 0.47
  
  stellar mass in solar units min-max 0.35 0.555
  
  period in days min-max 3.208 3.21
  
  duration in hours min-max 1.351 1.534
  

  K2 Targets within search area
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  212138198 126.0236 22.7833 0.14 12.902 5
  212137235 126.0099 22.7643 82.03 13.112 5
  212140084 126.0259 22.8231 143.53 14.639 5

  

  Posted February 10, 2016 5:34 PM

• by ajamyajax

  Re 211424769 from Martti's list: could be a binary with this V-fit and a possible faint secondary.

  s1=2311.494 p1=5.17685 d1=0.08 (1.92 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211424769 , 2MASS J08352466+1200420 , 8.277 , 7.998 , 7.949 , 0.279 , 0.049 , ('G1V', 1.07) , ('F1V', 1.5)

  au min-max 0.045 0.05
  
  stellar diameter in solar units min-max 0.45 0.545
  
  stellar mass in solar units min-max 0.455 0.62
  
  period in days min-max 5.169 5.186
  
  duration in hours min-max 1.84 2.012
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211424769 128.8527 12.0116 0.19 9.438 5
  

  BD+12 1868 -- Star per Simbad, Proper motions mas/yr : -82.5 -71.9, Spectral type: F8

  

  Posted February 10, 2016 6:43 PM

• by ajamyajax

  Re 211924657 from Hans Martin's list: could be a nicely heated up sub-Neptune planet candidate with another possible gas or debris trail (if not R8 residuals). And only a 0.60x R_sol estimate.

  s1=2309.003 p1=2.64415 d1=0.0725 (1.74 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211924657 , 2MASS J08400641+1905346 , 12.183 , 11.605 , 11.370 , 0.578 , 0.235 , ('K5V', 0.75) , ('M3V', 0.4)

  au min-max 0.03 0.035
  
  stellar diameter in solar units min-max 0.525 0.685
  
  stellar mass in solar units min-max 0.515 0.82
  
  period in days min-max 2.641 2.649
  
  duration in hours min-max 1.647 1.84
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211924657 130.0268 19.0929 0.11 15.031 5
  

  

  Posted February 10, 2016 6:46 PM

• by ajamyajax

  Re 211906650 from Hans Martin's list: only two transit events, but maybe another mini gas giant planet candidate here if not glitches. 0.96x R_sol estimate.

  s1=2321.845 p1=41.465 d1=0.25 (6.0 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211906650 , 2MASS J09012038+1849316 , 11.142 , 10.840 , 10.774 , 0.302 , 0.066 , ('G3V', 1.0) , ('G0V', 1.09)

  Semi-Major Axis a (A.U.) = 0.236
  
  Stellar diameter ratio = 0.96
  
  Stellar mass ratio = 1.0213
  
  Period ~= 41.46 days
  
  Duration ~= 6.0 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211906650 135.3350 18.8255 0.18 12.193
  

  

  Posted February 10, 2016 11:43 PM

• by ajamyajax

  Re 211770795 from Hans Martin's list: more candidates here than I remembered.. Regarding a multi mention by HM; I could only get three or more repeat events for one possible PC transit here. But others could be there and more blended. 0.73x R_sol estimate.

  s1=2308.10 p1=7.727 d1=0.12 (2.88 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211770795 , 2MASS J08480233+1654067 , 12.841 , 12.265 , 12.174 , 0.576 , 0.091 , ('K5V', 0.75) , ('K0V', 0.89)

  au min-max 0.065 0.075
  
  stellar diameter in solar units min-max 0.66 0.81
  
  stellar mass in solar units min-max 0.615 0.945
  
  period in days min-max 7.717 7.734
  
  duration in hours min-max 2.783 2.98
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211770795 132.0097 16.9019 0.21 14.489 5
  
  211772294 131.9992 16.9235 85.96 17.056 5
  
  211770667 131.9751 16.9002 119.45 12.263 5
  

  

  Posted February 10, 2016 11:45 PM

• by ajamyajax

  Re 211770696 from Hans Martin's list: maybe another subgiant and another planet candidate to consider here. 1.57x R_sol estimate.

  s1=2312.975 p1=16.27 d1=0.30 (7.2 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211770696 , 2MASS J08310268+1654020 , 11.186 , 10.895 , 10.804 , 0.291 , 0.091 , ('G1V', 1.07) , ('G9V', 0.91)

  Semi-Major Axis a (A.U.) = 0.126
  
  Stellar diameter ratio = 1.57
  
  Stellar mass ratio = 1.0145
  
  Period ~= 16.28 days
  
  Duration ~= 7.2 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211770696 127.7612 16.9006 0.13 12.253 5
  

  

  Posted February 11, 2016 12:22 PM

• by ajamyajax

  Re 211606790 from Hans Martin's list: only two transit events, but this one looks like a binary.

  s1=2317.09 p1=37.247 d1=0.18 (4.32 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211606790 , 2MASS J09083465+1437511 , 10.860 , 10.488 , 10.398 , 0.372 , 0.09 , ('G9V', 0.91) , ('G9V', 0.91)

  au min-max 0.19 0.19
  
  stellar diameter in solar units min-max 0.61 0.63
  
  stellar mass in solar units min-max 0.66 0.66
  
  period in days min-max 37.235 37.235
  
  duration in hours min-max 4.255 4.394
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211606790 137.1444 14.6309 0.15 12.673 5
  
  211607088 137.1112 14.6352 116.82 16.664 5
  

  

  Posted February 11, 2016 12:23 PM

• by ajamyajax

  Re 211682544 from Hans Martin's list: another with two transit events in the more corrected data, but this one looks more like a PC. However the duration seems too short for the stellar parameters the colors suggest anyway. So this could also be either a binary or a blend where the actual PC duration is greater in my opinion.

  s1=2312.57 p1=50.81 d1=0.15 (3.84 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211682544 , 2MASS J08384378+1540503 , 10.216 , 9.814 , 9.748 , 0.402 , 0.066 , ('K0V', 0.89) , ('G0V', 1.09)

  Semi-Major Axis a (A.U.) = 0.202
  
  Stellar diameter ratio = 0.43
  
  Stellar mass ratio = 0.429
  
  Period ~= 50.82 days
  
  Duration ~= 3.84 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211682544 129.6824 15.6806 0.11 11.407 5
  

  

  Posted February 11, 2016 7:31 PM

• by ajamyajax

  Re 211355342 from Hans Martin's list: another good planet candidate although this duration could be longer and the star size greater also, if the colors are correct. 0.78x R_sol estimate.

  s1=2310.8 p1=6.8935 d1=0.12 (2.88 hours +)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211355342 , 2MASS J08301297+1054371 , 11.438 , 11.082 , 11.026 , 0.356 , 0.056 , ('G8V', 0.94) , ('F5V', 1.32)

  au min-max 0.06 0.07
  
  stellar diameter in solar units min-max 0.68 0.85
  
  stellar mass in solar units min-max 0.605 0.965
  
  period in days min-max 6.886 6.901
  
  duration in hours min-max 2.784 2.976
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211355342 127.5540 10.9103 0.12 12.637 5
  

  

  Posted February 11, 2016 7:33 PM

• by ajamyajax

  Re 211579683 from Hans Martin's list: this one appears blended, but still a possible mini gas giant planet candidate. 0.78x R_sol estimate.

  s1=2311.605 p1=9.014 d1=0.13 (3.12 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  211579683 , 2MASS J08205149+1415311 , 12.511 , 11.970 , 11.856 , 0.541 , 0.114 , ('K3V', 0.81) , ('K3V', 0.81)

  au min-max 0.08 0.08
  
  stellar diameter in solar units min-max 0.755 0.8
  
  stellar mass in solar units min-max 0.84 0.84
  
  period in days min-max 9.017 9.017
  
  duration in hours min-max 3.029 3.21
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  211579683 125.2146 14.2587 0.21 14.029 5
  
  211578805 125.1956 14.2462 79.91 16.666 5
  

  

  Posted February 12, 2016 7:19 PM

• by ajamyajax

  Re 212009016 from Hans Martin's list: also blended and more speculative, but maybe three or more new planet candidates here. 0.84x R_sol estimate.

  s1=2331.69 p1=37.28 d1=0.224 (5.37 hours)

  s2=2313.0 p2=16.38 d2=0.17 (4.08 hours)

  s3=2311.17 p3=14.88 d3=0.12 (3.95 hours)

  EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

  212009016 , 2MASS J08245766+2024126 , 11.617 , 11.120 , 11.043 , 0.497 , 0.077 , ('K3V', 0.81) , ('G6V', 0.97)

  Semi-Major Axis a (A.U.) = 0.2077
  
  Stellar diameter ratio = 0.84
  
  Stellar mass ratio = 0.86
  
  Period ~= 37.28 days
  
  Duration ~= 5.37 hours
  

  au min-max 0.12 0.12
  
  stellar diameter in solar units min-max 0.82 0.86
  
  stellar mass in solar units min-max 0.86 0.86
  
  period in days min-max 16.372 16.372
  
  duration in hours min-max 3.982 4.176
  

  Semi-Major Axis a (A.U.) = 0.1126
  
  Stellar diameter ratio = 0.84
  
  Stellar mass ratio = 0.86
  
  Period ~= 14.88 days
  
  Duration ~= 3.95 hours
  

  From NEA, K2 Targets within search area:
  
  EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number
  
  212009016 126.2403 20.4035 0.08 13.092 5
  
  212008882 126.2662 20.4013 87.81 15.810 5
  

  

  Update:

  Whew, and I am finally through with closer looks at most of these C5 candidates also. Due credit to all those who posted here, but especially to Hans Martin and Martti for their excellent finds. And Ivan for the UKIRT images and more of course.

  C5 is an exceptional campaign rich with planet candidates and sure was enjoyable to work with. Let's hope it is just as rewarding to everyone in the main PH interface whenever it gets there. Good luck to all, as always. Mark

  Posted February 12, 2016 7:21 PM

• by Dolorous_Edd

  EPIC 212138198

  UKIDSS J-band

  Yep, there is a close star less than 1" to the E

  

  Posted February 16, 2016 8:18 AM

• by Dolorous_Edd

  EPIC 211424769

  There is Subaru image available, but it is nearly useless thanks to a white stripe in the middle

  nothing suspicious in DSS though

  

  Posted February 16, 2016 8:28 AM

• by Dolorous_Edd

  EPIC 211924657

  Was imaged by Subaru telescope

  Field is not clean, but we should worry about only about possible star to the NW ~4.5" other objects are most likely galaxies

  

  In SDSS looks like M type star

  SDSS J084006.42+190533.8

  

  Posted February 16, 2016 8:42 AM

• by ajamyajax

  Revisiting 211939692 with the new Aigrain et al. corrections: just noting the transit-like events seem connected to a possible stellar flux cycle every 23-25 days.

  

  And the new Aigrain et al. corrections are available here (C3-C6 so far):

  https://archive.stsci.edu/prepds/k2sc/

  https://archive.stsci.edu/k2/hlsp/k2sc/search.php

  Posted April 8, 2016 5:27 PM

• by Shellface in response to ajamyajax's comment.

  [is a skeleton]

  Bleigh! I have escaped from purgatory! That took way longer than I had hoped or expected. Life is hard! My grave apologies to everyone.

  Back in January, zoo3hans asked me to take a look at EPID 211939692, and kindly provided me with a lightcurve reduction. I did so right away and reached most of my conclusions, then promptly came down with a debilitating cold. Subsequently I had no time for anything except education, hence it took 6 months to finally get here.

  Since then, Vanderburg's reduction of the C5 lightcurves has (obviously) been released. Comparing the two reductions indicates the one zoo3hans provided is slightly better behaved. I will use that here, but the differences in the results should be negligible.

  EPID 211939692: aja's comment paints a very interesting picture of this system. A bright star (V = 11.5), the lightcurve shows six clear transits, none of which are clearly related by periodicity. Such a complex system will take some care to understand.

  The star has B and V colours, but they are mostly useless due to their errors of 0.1-0.15 mag. Using infrared colours is not favourable for early-type stars as the changes in colour index are slow, but they will have to suffice. A weighted average of the V-K and J-H give a spectral type of F5 ± 3 (~6500 ± 300 K), with an unfortunately large error. Galactic reddening in the direction of the star is vanishingly small, so this temperature should be appropriate.

  On the Hertzsprung-Russell diagram, the distribution of mid-F dwarfs and subgiants are roughly continuous, as evolving stars take some time to cool appreciably even though they are beginning to inflate. Thus a mid-F star without known distance can span a relatively large range of luminosities and radii, despite being well-constrained in temperature. As no method available to me is able to break this degeneracy, spectroscopy will likely be necessary; the below parameters may need revision as a result.

  The star appears to be single beyond 2", with no other point sources appearing in 2MASS within 20", no other objects in the EPIC in the same distance, and no nearby objects in SIMBAD.

  The lightcurve is dominantly composed of an upward trend; the long period of variability indicates it is systematic in nature. Below this, there is a signal with a period of ~29 days plus up to perhaps the fourth harmonic which may be due to rotation. Though the semi-amplitude of variability is extremely weak (200 ppm), this is not too unusual for a star above the Kroft break, as stellar magnetism weakens considerably with the disappearance of the convective zone. More concerning is that the period is extremely long for an F-star, even for a subgiant, which suggests the month-long period is not the rotational period.

  As stated before, there are six transits apparent in the lightcurve. Repeating the times and durations given in aja's comment:

  s1=2333.05 d1=0.40 (9.6 hours)

  s2=2337.50 d2=0.50 (12.0 hours)

  s3=2341.00 d3=0.40 (9.6 hours)

  s4=2358.90 d4=0.57 (13.68 hours)

  s5=2359.90 d5=0.40 (9.6 hours)

  s6=2380.52 d6=0.40 (9.6 hours)

  The lightcurve begins and ends at (BJD-2454833) = 2307.55 and 2381.41, respectively. Importantly, there is a 25-day interval starting at the beginning of the lightcurve where no transits are present; this is very valuable for constraining possible periodicities in the transits.

  The two longest transits present, 2 and 4, are also the deepest. They are dissimilar with each other and any of the other transits, so they are monotransits. Without repeats transits are more difficult to study, so I will set these two aside for now.

  The remaining four transits have similar durations and depths, indicating there might be some degree of association between them. Though they clearly cannot be explained as a single periodicity, it is possible that that can be paired in sets of two. The combinations that are compatible with the lack of additional transits are:

  • 1 + 5 (26.9 days)
  • 1 + 6 (47.5 days)
  • 3 + 6 (39.5 days)

  The 1 + 5 and 3 + 6 pairs are compatible with each other, and barely compatible with the lack of additional transits (the 1 + 5 pair predicts a transit 1.3 days before the start of observations). They also imply a period ratio of ~1.47, close to 3:2, which is not likely to occur by chance. Meanwhile, the 1 + 6 pair would leave 3 and 5 as monotransits, as a 3 + 5 pair would predict a transit at 2322.1 that is not observed, but this seems unlikely given that all four transits have similar durations. Hence, I assume that the 1 + 6 pair is invalid.

  Next comes the transit modelling. As the 3 + 6 pair has better transit coverage and higher S/N than the 1 + 5 pair, I will fit the 39.5-day signal first.

  I fed the two transits into EXOFAST with a Teff prior of 6500 ± 300 K (plus a weak prior on i so that the impact parameter would not get stuck at 90°). The output was as follows:

  

  The two transits agree very well in shape and depth, which can be clearly seen when they are directly compared:

  

  (Blue is transit 3, red is transit 6)

  The lack of limb darkening, to be expected of a hot star, means that the transit depth can be derived from simple averaging. From this, the depth of transit 3 is 523 ± 63 ppm while the depth of transit 6 is 499 ± 60 ppm, which agree to less than 1σ. That, combined with the identical lengths and ingress/egress slopes, is enough for me to consider the association of these two transits undeniable.

  The derived stellar parameters place the star above the main sequence, but it should be clearly noted that their derivation is highly sensitive to the modeled impact parameter, which is not very well constrained. Again, spectroscopy will be important for deriving accurate parameters.

  Next comes the 1 + 5 pair. I used the same priors as above, plus a log g prior to match 39.5-day fitted parameters (mostly for the sake of comparison, though the poor egress coverage on these transits make it valuable). This was the result:

  

  Poorer coverage over the second half of the transits makes direct comparison less useful, but the similarity between the two transits remains obvious:

  

  The depth of transit 1 is 416 ± 61 ppm, while the depth of transit 5 is 412 ± 83 ppm; though there are less points to work with, the excellent agreement is strong evidence for the equality of the transits.

  The similarity of the stellar parameters in the two models should not be taken at face value, as the model for the 26.87-day signal is essentially forced to match that of the 39.53-day one. And, again, the stellar parameters remain subject to revision.

  With four of the transits accounted for, only the two monotransits are left. It is not possible to solve the period of a companion from a single transit in a "pure" manner due to the degeneracy between period and semi-major axis (and eccentricity, though that is usually ignored) in the equation for transit length. Knowledge of the stellar density radius (and assumptions on eccentricity) are enough to place constraints on the period, the method being described in this paper, but this this is sensitive to the impact parameter, which is poorly constrained for all transits in this lightcurve. Thus, I will not venture as far as attempting to constrain the periods of the monotransiters physically, only observationally, but will note that constraints may be possible with better transit modelling.

  

  Transit 2 is the deepest of the six. The latter part of the transit, including its egress, is mangled in the reduction (this can also be seen in the Vanderburg reduction), hence the its length is difficult to constrain; EXOFAST formally gives 0.492 ± 0.005 days, but this is susceptible to overfitting due to the small dataset and should not be taken at face value. The ingress and early transit shows noticeable curvature, suggestive of limb darkening and a non-negligible ingress duration, which in turn indicate the transit may have a significant impact parameter.

  The transit depth is 974 ± 32 ppm; assuming that the effects of limb darkening are negligible, this gives a radius of 0.46 Rjup for R = 1.49 Rsol.

  The lack of other transits in the lightcurve indicates P > 43.9 days, and it is likely significantly longer.

  

  Transit 4 is not much deeper than the periodic transits. EXOFAST gives a transit duration 0.454 ± 0.009 d, which is likely accurate. The transit does not show much limb darkening or much of an ingress, so it seems that the impact parameter is small.

  The transit depth here is 584 ± 60 ppm, which gives r = 0.36 Rjup for R = 1.49 Rsol, a value barely different than for the 39.5-day signal.

  The lack of other transits in the lightcurve indicates P > 51.3 days. Given the similar transit duration to the 39.5-day signal, it is plausible that the actual period is not much longer than this.

  What are the prospects for determining the periods of the monotransiters? The transits are too shallow and too long-period to be observed from the ground, and with current space missions it would be necessary to have at least a general idea of when to observe transits, which we do not have; while solving the orbital period with RVs is mildly feasible due to the brightness of the star, its high temperature makes this much more difficult. Thus, it seems likely that the period of the monotransiters is not determinable beyond statistical inference for the foreseeable future.

  Are the signals planetary? Kepler showed that most multi-transit systems are physical, so the false positive probability for a four-transit system is probably negligible. The transit durations and period constraints are compatible with all six being associated with the same star; there also seems to be a monotonic relationship between companion radius and duration (itself linked with period) which seems unlikely to be coincidental. Though I cannot strongly constrain the stellar radius, the companion-star radius ratios of ~0.020 - ~0. 031 are within the planetary range for all plausible stellar radii (~1.1 - ~2 Rsol). Thus all four companions are likely planetary.

  Because there are at most two transits per planet in this lightcurve, this system cannot be identified by conventional algorithm because they usually require 3 transits to consider a signal a detection. Indeed, this system is not picked up by the recent publication of Pope et al., who use a fairly standard detection metric. It may be down to PH to study this system, as it was for some of the long-period Kepler candidates with only two transits.

  Though not an ideal system for characterisation due to the hot host and uncertain orbital periods, the star is fairly bright and validation, if not confirmation, should be feasible. An extreme system for K2, but not unusual among Kepler systems, this may be a valuable system for study in future as a bright analogue of some Kepler systems.

  (Also, I've obviously been a bit out of it recently so I don't know for certain, but would this be K2's first four-companion system?)

  Posted June 13, 2016 9:51 PM

• by ajamyajax in response to Shellface's comment.

  SF, awesome to see you back and posting again! We have certainly missed your wonderful insights here. And I realize you are a contrarian at heart, but as of today I am hoping for regular posts from you again like "the good old days." And I know, who's old.. Well I am at 58, so it fits. But only on the outside lol. And all that life stuff is just for contrast to your education and skeleton comments. 😉

  Anyway, back to 211939692: while you were gone we got a new set of corrected data from another team (Aigrain et al.) Here are their links:

  https://archive.stsci.edu/prepds/k2sc/

  https://archive.stsci.edu/k2/hlsp/k2sc/search.php

  That is pertinent here only because I plotted and posted this target's LC from their work on PH soon after their data was released:

  

  I will let you judge this for yourself without prejudice except to say it may -- or may not -- be more correct than Andrew's or MAST (I have made a habit of picking on all three of the corrective efforts' data from time to time and with good reason I believe, which you could browse here some other time). And they know all the flaws I'm sure, just wanted to be sure we do also.

  Anyway, I also did a quick survey and if you are correct about four PCs here it could be the first of those in K2.. Hans Martin's and Andrew's 206103150/WASP-47 has planets designated as b,d,e (but no c). Hmmm, can't recall what that was all about. Here is the only real table we have so far though:

  http://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=k2candidates

  There was one other C5 system -- Martti's find -- we looked at that might have four candidates (see some of my comments below). And you might find that one interesting to analyze too sometime. So again, welcome back and hope to see more posts when you can and want to thrill the crowd!

  Sincerely, "aja"

  ...

  Re 211311380 revisited: Yes a MPC, and with more corrected data looks like two to four gas giants possible here. Only one transit repeats which makes the other periods true estimates however. And the chances of glitches increase with these single events, too. It also concerns me that three possible longer-period transits appeared in the same short period window. And some could even be stars.. But all that considered, still an interesting candidate system.

  ...

  s1=2319.275 p1=15.575 d1=0.21 (5.04 hours) ~2.42Re

  s2=2309.02 p2=235.9 d2=0.52 (12.48 hours) ~5.06Re

  s3=2333.31 p3=185.73 d3=0.48 (11.52 hours) ~3.84Re

  s4=2353.91 p4=796.5 d4=0.78 (18.72 hours) ~9.27Re

  etc.

  Posted June 13, 2016 11:50 PM

• by zoo3hans in response to ajamyajax's comment.

  Wasp-47 has at least 4 planets, 3 transiting ones and a large outer non-transiting planet (detected only by RV measurements). See for example https://wasp-planets.net/2015/08/15/four-planets-around-wasp-47/

  Posted June 14, 2016 8:31 AM

• by ajamyajax in response to zoo3hans's comment.

  Oh yes, your two nice finds HM, plus the HJ, plus a longer period planet so far. Thanks!

  http://www.openexoplanetcatalogue.com/planet/WASP-47 b/

  Posted June 14, 2016 1:44 PM

• by ajamyajax in response to ajamyajax's comment.

  Also if it interests, here are some newer images of Martti's possible MPC 211311380 with my transit estimates drawn on both Andrew's and Aigrain's corrected data. And not shown but MAST data also shows the larger possible transits, but the shorter period event there has one that is possibly blended. Also I just looked and there don't appear to be any papers referencing this system yet. Also VSX and Simbad do not list any nearby binaries. Plus the closest EPIC does not show any obvious sign of these transits.

  
  

  Posted June 15, 2016 4:17 PM

• by Shellface in response to ajamyajax's comment.

  Thank you for the warm welcome, aja 😃

  And I realize you are a contrarian at heart

  Eh, I am? That's news to me.

  I hope to be able to do regular-type analyses for at least the next couple of months. I'll probably cover some of the more interesting (and/or easier)-looking systems from the last few Campaigns, and there's also some K1 stuff I would like to cover.

  At first glance, the lightcurves from Aigrain et al. look rather noisy - there seems to be a lot of sub-day variability which looks a lot like the regular unprocessed K2 systematics. The 6 transits on EPID 211939692 all look quite mangled, and the two more that you pick out don't look very convincing - is this really a proper lightcurve reduction?

  EPID 211311380 looks very interesting. As should be obvious I cannot deal with monotransits very well, but this looks like a much more interesting target for followup (V = 8.9! RVs look very feasible), so I think I'll look at this right away.

  Anyway, I look forward to being useful, at least for now!

  Posted June 16, 2016 12:36 AM

• by ajamyajax in response to Shellface's comment.

  Ok, great! And sorry for the other bit, you were probably just busy before.. Real life stuff always comes first... I'm semi-retired, so I just chug along with the closer looks as long as I can manage it anyway. 😃 But I think we are making progress with constraints and identifications and things of that sort. So hope to get some of your capable help there again when you are able to.

  Posted June 16, 2016 4:50 PM

• by Artman40

  http://arxiv.org/abs/1606.05818

  EPIC 211351816.01: A (Re-?)Inflated Planet Orbiting a Red Giant (4.20 ± 0.14 Rsun) Star.

  Planet radius and mass: 1.27 ± 0.09 RJ and 1.10 ± 0.11 MJ.
  Orbital period: 8.4080 days.

  Posted June 21, 2016 12:54 PM

• by Shellface

  EPID 211311380: Though a lightcurve dominated by monotransits, I will try my best to interpret the system structure.

  As this star is bright among K2 targets (Kep = 9.1, V = 8.9), it has excellent photometric quality as well as a Hipparcos parallax (8.56 ± 1.24 mas = 116.8 ± 17.3 pc). Its colours give a spectral type of F7.5 ± 1.5 = 6200 ± 150 K for small reddening, which compares well with the Huber et al. value of 6086 ± 216 K. Huber et al. give an Fe/H of 0.05 ± 0.12; as this is purely photometric this may not be accurate, but it indicates the star is not extreme in metallicity. I assume Fe/H = 0.0 ± 0.3 here.

  As information on the star's brightness, temperature, metallicity and distance are available, it is possible to perform some rudimentary isochronal modelling. From this I obtain M = 1.17 ± 0.12 Msol, R = 1.39 ± 0.19 Rsol, and log g = 4.19 ± 0.11 cgs, again compatible with the Huber et al. values. Though the uncertainties are fairly large, the luminosity of 3.15 ± 1.01 Lsol consistently places the star around the main-sequence turnoff. More accurate parameters will be possible with spectroscopic values for Teff and Fe/H (plus an eventual improved parallax), but here I will use the log g as a prior in the transit fitting.

  No objects beyond 2" that could contaminate the Kepler lightcurve seem to be present. Additionally, none of the stars in the EPIC at up to 1.4' (10000 AU projected) seem to be compatible with being bound to the target, so unless there is a close companion, the star is quite likely single.

  This lightcurve shows the same trend as EPID 211939692, confirming that it is systematic. A signal at ~28 days is also found here, suggesting it may also be residual systematics. However, there does not appear to be further variability at the 100ppm level in this lightcurve, indicating the ~14 day period in EPID 211939692 may be the rotational period for that star. Here, the lack of rotation is not too unusual for a turnoff star, particular an F-type one.

  Previous comments have found one periodic signal in the lightcurve, plus three monotransits. During detrending I identified an additional weak and possibly periodic signal, which I will discuss later. Borrowing the Kepler notation, I will refer to the identified periodic signal as .01, the monotransits as .02 - .04 in order of their appearance in the lightcurve, and the candidate new signal as .05. I will discuss .01 first.

  I selected the transits belonging to .01 and fed them into EXOFAST with Teff = 6200 ± 150 K and log g = 4.19 ± 0.11 cgs. This was the output:

  

  EXOFAST seems to prefer a high impact parameter, but I cannot see any reason why and a model with i = 90° has equal reduced chi-square. Calculation of impact parameter is sensitive to the non-total contact duration of a transit which are difficult to measure for low S/N transits, so I expect the output of b = 0.6 is not very statistically significant.

  Overall the fit is good, with the rms being an impressive 40 ppm. There appears to be slight excess scatter around egress, but it does not appear to impact the model much. For the isochronal stellar radius of 1.39 ± 0.19 Rsol, the companion radius is 2.84 ± 0.39 Rearth, which is in the sub-neptune range.

  Next come the monotransits. I will discuss them in order of depth, largest to smallest. For their EXOFAST models I will use first-guess values for their orbital periods. EXOFAST seems to have a strange idea of what transit length actually means, hence one must use a "right" value for P in order to get correct outputs, even though P should have no impact on the model for monotransits.

  The deepest transit belongs to .04, which is also the longest by a considerable margin - at about 19 hours in length, this will likely be one of the longest transits K2 will observe around a non-giant star. The long transit means that the ingress and egress are clearly resolved even with Kepler's 29.4-minute integration time, which means the transit shape is well-constrained.

  Using the same priors as before, the transit of .04 was fed into EXOFAST with a guess period of 400 days. The output model was the following:

  

  Owing to the resolved ingress/egress the impact parameter is decently constrained, though it appears to be consistent with zero to reasonable confidence.

  Though the transit depth is intermediate (5200 ppm), the large stellar radius means that the companion radius is Jovian. For R = 1.39 ± 0.19 Rsol, the companion radius is 0.99 ± 0.14 Rjup, broadly consistent with expectations for a cool gas giant. As the error on r/R is negligible, decreasing the error on R will be necessary to reach the precision on r necessary to test planet structure models, which has scarcely been done for non-Hot Jupiters.

  Next is .02, about 3.5 times shallower than .04. The transit length is also large, about 13 hours, hence the ingress/egress are somewhat resolved, giving decent constraint to the impact parameter.

  Roughly 4 hours of the transit, from just after ingress to the midpoint, are oddly offset from the rest. I suspect this is a processing issue as the feature does not appear in the raw lightcurve. As the second half is fine I choose to exclude this part of the lightcurve, but an improved reduction is desirable.

  Using the same priors and a guess period of 135 days, the lightcurve model was as follows:

  

  Again the impact parameter is constrained, but is consistent with zero.

  For R = 1.39 ± 0.19 Rsol, the companion radius is 0.535 ± 0.073 Rjup (5.87 ± 0.80 Rearth). This lies in a paucity of the planetary radius distribution, the sub-Saturn desert at ~5 - ~7 Rearth which corresponds with the paucity in mass at 30 - ~80 Mearth. According to core accretion planet formation models these are "failed gas giants", and they are quite uncommon, so it is somewhat remarkable to find one here.

  The last monotransit is .03. At about a third of the depth of .02 and a duration of roughly 10 hours, this is the shortest and shallowest of the monotransits.

  In the Vanderburg reduction the transit is considerably deeper just after ingress than before egress, and there is also a sharp spike just before ingress, giving the transit a lopsided appearance. Examination of the raw lightcurve shows the same feature, so this is likely caused by inaccurate identification of in-transit outliers in the reduction. A re-reduction with this in mind should be able to fix the issue, but as it affects most of the transit I cannot simply exclude that data here. Thus note that the transit shape shown below is not physical, and the transit parameters may be incorrect to a moderate degree.

  With the aforementioned priors and a guess period of 90 days, the EXOFAST model output is shown below:

  

  Here, the impact parameter seems to be significant. The egress, which is the only part of the transit not affected by the systematic error, is as long as the egress of .04 despite the transit itself being about half as long, which evidently necessitates a high impact parameter. This is somewhat surprising, as it ought to be the shortest-period of the monotransiters based on the transit length and one would naively expect increasing impact parameter with increasing period.

  For R = 1.39 ± 0.19 Rsol, r = 0.349 ± 0.048 Rjup (3.83 ± 0.52 Rearth). This is compatible with the radii of the solar system ice giants, and is not too remarkable among known planets.

  Last is the tentative signal, .05. The two events that I noticed occur at 2330.17 and 2361.86, separated from all other transits by at least a day. Though they could pass off as simple glitches on their own, they do not coincide with mentioned glitch areas within their durations and, more convincingly, they are rather alike:

  

  At the spacing of the two observed transits, the previous and following transits would be outside the lightcurve by many days, so the lack of additional transits is not unexpected. Based on their similarity I assume the two transits are due to the same object, with a period of 31.696 days. Interestingly, this leads to a period ratio of 2.036 with .01, comparable with the many near-resonance systems discovered by K1; this seems unlikely to be coincidental, so it somewhat supports the transits being real. One would expect TTVs detectable at K2's precision, but the super-period is ~900 days, so variations on the timescale of K2 observations should be negligible.

  What is most remarkable about these transits is their short duration. In total the transits last ~4.5 hours, comparable to the length of the transits of .01 despite twice as long a period. This plus how the the ingress/egress are apparently resolved in the LC observations suggest the transiter has a high impact parameter. Because of this it is difficult to model the lightcurve with EXOFAST, thus proper parameters are difficult. By trying varying inputs it seems the impact parameter is constrained to about b > 0.6 (i < ~89°), but models with impact parameter well over 1 are not empirically disfavoured.

  Without an upper constraint on b the radius ratio is also unconstrained, thus I can only give r/R > ~0.017. A more proper study of the transits considering physical constraints ought to give a moderate constraint to b, but that is beyond my capabilities. For R = 1.39 ± 0.19 Rsol, r > ~ 2.6 ± 0.4 Rearth.

  The apparent ~grazing nature of the transits of .05 are in contrast with the fact that the monotransiters transit, since an inclination below 89° would barely be transiting for the nominal parameters of .03. As the transits of .01 are compatible with inclinations down to ~88°, this suggests there may be a small-but-significant mutual inclination between the inner and outer companions.

  For EPID 211939692 I avoided estimating the periods of the monotransiters due to poor constraints on the impact parameters, but here the constraints are fairly decent, and in fact the weak constraint on b for .01 is more of a limiting factor in this case. I will make some attempts to constrain the periods here.

  Osborn et al. give the following equation for the period of a transiting companion with negligible eccentricity and mass ratio:

  P = (8π^2G) / 3 * ρ* / v '^3

  Where v ' = (2√(1+r/R)^2 - b^2)/T(1,4). Unfortunately they don't state their units, and I can't seem to figure out the right ones, so I'm going to use the physicist cheat of "make everything unitless ratios". If you divide the first equation through by a separate example of itself, the result is:

  P(1) / P(2) = v '(2)^3 / v '(1)^3, i.e the period ratio is equal to the ratio of transit velocities cubed.

  Since the equation for v ' is based on three transit observables (radius ratio, impact parameter, and transit duration), the process to derive the period ratios is thus relatively straightforward. As I do not have error bounds on the impact parameters I make some moderate assumptions on their values; as these subsequently dominate the error budgets, I ignore the errors on r/R and T(1,4) here.

  For .04, I assume b = 0.2 ± 0.2 and derive v ' = 2.65 ± 0.10 R* / d

  For .02, I assume b = 0.2 ± 0.3 and derive v ' = 3.77 ± 0.24 R* / d

  For .03, I assume b = 0.4 ± 0.2 and derive v ' = 4.73 ± 0.44 R* / d

  In the case of .01 there does not appear to be a preferred impact parameter, hence I assume minimum and maximum values of b = 0.0 and 0.7 with a flat probability distribution. These give v ' = 9.57 R* / d and v ' = 6.95 R* / d, respectively.

  I did not calculate v ' for .05 because of the unconstrained impact parameter.

  Because .01 has a known orbital period of 15.571 days, it is most useful to calculate the period ratios of the monotransiters with respect to .01, even though its impact parameter is weakly constrained. In the b(.01) = 0.0 case:

  P(.04)/P(.01) = 47.1 ± 5.4, P(.04) = 733 ± 84 days

  P(.02)/P(.01) = 16.36 ± 3.17, P(.02) = 254 ± 49 days

  P(.03)/P(.01) = 8.28 ± 2.38, P(.03) = 130 ± 37 days

  And in the b(.01) = 0.7 case:

  P(.04)/P(.01) = 18.03 ± 2.06 , P(.04) = 281 ± 32 days

  P(.02)/P(.01) = 6.27 ± 1.21 , P(.02) = 97.7 ± 18.8 days

  P(.03)/P(.01) = 3.17 ± 0.91 , P(.03) = 49.4 ± 14.2 days

  The real value of b(.01) is likely somewhere inbetween, hence these should be considered upper and lower limits to the periods of the monotransiters.

  Because the impact parameters of the monotransiters are better-constrained than the impact of .01, the period ratios of the monotransiters relative to each other are better determined than their periods relative to .01. Though they do not have an absolute "anchor" to find the periods yet, the period ratios should be correct as long as the assumed values of b are. Thus:

  P(.04)/P(.02) = 2.88 ± 0.89

  P(.02)/P(.03) = 1.97 ± 0.96

  P(.04)/P(.03) = 5.69 ± 2.27

  These are relatively small ratios, and they suggest that the monotransiters are fairly tightly spaced. It is possible - or perhaps likely - that they are in resonances, though the errors are too large to elucidate which. It may also be that .05 and .03 have a period ratio close to resonance, but again the errors are too large to call anything much.

  Overall the system architecture here is comparable to Kepler-90, a system familiar to some of you. It does not appear to span down into the terrestrial planet range, but it covers a similar amount of space (1 - 2 AU) and reaches much of the radius range of planets. However, a key difference is that the host star is ~100 times brighter, so while RV follow-up for Kepler-90 is a daunting idea with modern technology, it is fairly realistic here. I will now attempt to predict the RV semi-amplitudes of the companions.

  To find the RV semi-amplitude (K) we first need the companion masses. Using rough mass-radius relationships for planets, the companion masses should be:

  .01: ~6 Mearth

  .04: >~100 Mearth (giant planets are quite homogeneous in radius)

  .02: ~50 Mearth

  .03: ~15 Mearth

  .05: not much constraint is possible without a decent radius constraint.

  From this, and for M = 1.17 Msol, the expected RV semi-amplitudes over the predicted periods are:

  .01: ~1.4 m/s

  .04: ~6 - 100+ m/s

  .02: ~4.5 - ~6.4 m/s

  .03: ~1.7 - ~2.4 m/s

  These are within the realm of detectability around a V = 8.9 star, depending on the exact parameters. .04 is likely to be detectable under all plausible circumstances.

  As the star lies at a declination of +10°, it is observable from most of the Earth, including the most suitable spectrographs (HARPS, HARPS-N, HIRES). Though it obviously lies along the ecliptic, what with being a K2 star, it should be observable for several months of the year from these locations.

  Being such a bright star, photometric follow-up is worth considering. The transits are likely too shallow to observe from amateur facilities, except perhaps for .04 (though the weakly constrained period is a major issue, and the transit is too long to observe in a single night). Some of them ought to be observable by professional telescopes, given that the transits of 55 Cancri e (~300 ppm around a V = 6 star) have been detected by a 2m telescope, but the long transits of the monotransiters are a problem. Observations by Spitzer and the HST are plausible. Atmospheric characterisation is worth considering, but discussion of that is beyond my knowledge.

  This is an exceptionally valuable system. A bright analogue to what would be a notable Kepler system, this is well-suited for characterisation with modern and near-future instruments. Hopefully follow-up is as possible as I predict it is.

  As a footnote, Courcol et al. recently noted a relationship between planet mass and stellar metallicity for Neptunes and sub-Saturns, with more massive planets being missing around metal-poor stars. The top of their figure 1 roughly coincides with my predicted mass for .02, tentatively suggesting that the star may be rather metal-rich, which would agree with the large mass of the planetary system. This would be favourable for RV observation, because higher metal abundances deepen absorption lines which improves RV precision. Spectroscopic observations will be needed to explore this possibility.

  Posted June 22, 2016 11:49 PM

• by Artman40

  http://arxiv.org/abs/1606.08441

  And here is a discovery paper of a said star called "Five Planets Transiting a Ninth Magnitude Star".

  Posted June 29, 2016 4:50 AM

• by zoo3hans in response to Artman40's comment.

  Yes, this multiplanet system is EPIC 211311380 and has been reported here by Martti (on page 1) and by Mark and extensively by Shellface (on page 18). A fine system indeed.

  Posted June 29, 2016 8:44 AM

• by ajamyajax

  Congrats to Martti, Andrew, Al, and everyone involved in that paper! And as always, there is much more to do for anyone who has the time and interest of course.

  As I have said before too, the science and discovery should always come first. Let's see what exciting new things we can find in this data!

  Best to ALL, Mark

  Posted June 29, 2016 1:13 PM

• by Shellface

  Congratulations to Vanderburg and colleagues for another successful scoop, and to Martti for the recognition!

  The published results and the ones I gave on the last page compare quite well, which is rather encouraging. The differences for d (.03) are due to the systematics I talked about, which cut off about 3 hours of the transit, while the small differences for c (.05) are due to me detrending the transits a bit badly.

  The actual Fe/H of the star turns out to be -0.11 ± 0.08 dex, to which the Huber et al. value of 0.05 ± 0.12 is compatible. Thus, it seems the Courcol et al. relationship does not extrapolate to the size of e.

  Their model for the periods of the monotransiters is much superior to mine due to the consideration of eccentricity. The results for d and e are somewhat odd, because the period ratio seems like it may be even lower than what I evaluated it to be (on top of having the pair switched in period). Proper determination of the periods is very desirable.

  Posted June 29, 2016 6:18 PM

• by Shellface

  Now for something completely different.

  Messier 44, usually known as Praesepe or The Beehive, features prominently in the Campaign 5 field. One of the closest and brightest open clusters in the sky, has been an important target for stellar physics for many decades. Though open clusters have been sidelined in exoplanetary studies for various reasons, observational effort has picked up over the last few years. In the case of Praesepe results have been successful, as it currently houses three known planets in two systems.

  Open clusters provide broad advantages for the characterisation of stars and their planets, but identifying their members is not such a simple task. Lightcurves alone are not enough to identify cluster members, so PH planet candidates around such stars will not be distinct from field stars. It will take a concerted effort to identify the important cluster members, which I will attempt here.

  There are five principle ways to identify a star as a member of an open cluster:

  • Position. Clusters of all types form a cohesive entity that span a small area of the sky at most. In order to be bound to a cluster a star must be within a certain distance from its centre on the sky.
  • Proper Motion. As clusters form a bound entity, the orbits of their constituent stars about the galaxy are the same. As of such, their motion across the sky must be within a certain range around the cluster average.
  • Radial Velocity. The third component of the space velocity of a star, this follows the same logic as proper motion - all cluster members must be within a certain velocity difference of the cluster average.
  • Sequencing. Being a defined object in space, cluster members must lie at roughly the same distance, so their members form a cohesive Hertzsprung-Russell diagram in magnitude, as well as absolute magnitude. All members of an open cluster form approximately simultaneously as well, so they must all follow an evolutionary track of a certain age.
  • Metallicity. As an open cluster forms more or less instantaneously from the same natal star-forming material, all members must have equivalent metal abundances to a tight bounding.

  Note that all of these criteria have to be satisfied for a star to be a member, and the failure of any one constraint is enough to exclude the membership of a star.

  Radial velocities require spectroscopic observations, which are not currently available for most stars under consideration. Though photometric metallicities are possible, they are not very accurate, so they are best left for spectroscopy too. Thus there are three methods currently available. The most powerful is proper motion, because the motions of Praesepe are very distinct from the medians of the surrounding field stars. Next is sequencing, which can exclude most stars that have coincidentally similar proper motions. Last is position because the number of non-members of Praesepe is far greater than the number of members in the nearby sky, but it is still useful for identifying interlopers that survive the other criteria.

  The stars I chose to investigate were selected from zoo3hans' list. Stars in the EPIC are sorted by declination; they cross the cluster centre in the 2119nnnnn entries, so I included stars on the list between 211700000 and 212100000. I excluded stars with only a single transit because they are a pain to study, and also excluded some which are likely EBs. In the end, the target list included 41 stars.

  The reference paper for Praesepe I have used is Wang et al. (2014). They give clean constraints for proper motion and sequencing, but a less justified constraint on position. I adopt their constraints for the first two, but choose to use" 4 degrees from core" as my constraint for position, slightly larger than the tidal radius of the cluster and larger than their constraint (3 degrees)

  I collected proper motions and JK magnitudes for the stars from the EPIC. All stars had 2MASS colours in the EPIC, but four had no proper motions (211765775, 211916756, 211924657, 211970234), and I could not find proper motions for any of them. Thus I can only use sequencing as a constraint for these stars, and consider their results weaker than the rest.

  Shown below is the proper motion diagram for the target stars:

  

  The errors are small compared to the points, so they are omitted for clarity. The axes are the same as those used in figure 1 of Wang et al. for the sake of comparison. One star, EPID 211817229, falls off the plot with proper motions of -8, -377 mas/yr.

  The spread of proper motions is large, which is to be expected considering the majority of these will be field stars. Below is the same plot, focusing on the region around the cluster proper motions:

  

  The small point marks the mean cluster motions of -36.5, -13.5 mas/yr. The circles lie at Δμ = 4 and 9 mas/yr, and mark the limits adopted by Wang et al.; a 9 mas/yr limit includes almost all cluster members but will also contain a higher number of field stars, while within a 4 mas/yr limit stars will be about 50% cluster and 50% field. Four stars lie within the 9 mas/yr limit, numbered 211799258, 211804579, 211822797 and 211990866. One additional star, EPID 211919004 lies just outside the limit to 1σ errors, and as it is not much more work I opt to include it with the other stars.

  The five acceptable stars continue to the sequence testing, along with the four stars without proper motions. Here is the plot of J against J-K for the nine remaining stars:

  (Note that the correct data would be J - Ks, but K and Ks are nearly identical so the difference is negligible)

  

  Blue points are stars with proper motions, and orange without; errors in J are negligible on this scale. The green line is the Praesepe track estimated from known members in Wang et al. Two stars clearly do not agree with the the Praesepe sequence:

  • EPID 211919004 (blue), which was the marginal failure in the proper motion criterion. Lying a magnitude below the sequence, it is evidently a background star. The companion is a HJ candidate so I will likely study it anyway, but it is not a Praesepis ("bee"?)
  • EPID 211765775 (orange). Lying 2.5 magnitudes above the sequence it appears to be an M-dwarf far in the foreground, which is notable because Praesepe is quite nearby itself (~180 pc)

  The other seven stars match the Praesepe sequence. While the two earlier-type stars' position is unambiguous, the position of the five late-type stars is less clear because the sequence becomes vertical. As J-K does not change appreciably for J > 12 the stars could be foreground stars of later spectral type: to break the ambiguity a sequence in different passbands is needed, which Wang et al. provide.

  The second track uses PAN-STARRS bands, but transformations for SDSS bands into these magnitudes are given. I obtained the g, z and r colours for the late-type target stars from the DR12 and used the transformations given, which I plot below:

  

  Both errors are negligible on these scales. Again, the (thick) green line is the sequence from known members, while the thin line marks the rough location of multiple stars above the main sequence. All five stars are close to the sequence, though two provide worse matches:

  • EPID 211924657 (g - y = 3.35) lies most of a magnitude above the sequence, but it does lie along the sequence for multiple stars. It may be an interloper, but it may also be a multiple system member. Further observations will be necessary to determine which applies.
  • EPID 211916756 (g - y = 3.23) lies about 0.3 magnitudes below the sequence; this is just about compatible with the observed scatter, so it is acceptable within the errors.

  Thus, all of the late-type stars survive to some degree. The positions of the seven stars are shown below:

  

  The large shape roughly marks the location of the Campaign 5 FOV, while the circle marks the location of Praesepe (with radius 4°). Though six of the stars do indeed lie within the cluster, EPID 211970234 lies outside of the tidal radius of the cluster by some distance. This is the latest-type of the seven remaining stars and it does not have proper motions, though it agrees well with the sequences. Though it could possibly be an evaporated member of the cluster the density of such stars is expected to be < 2 per square degree, so the probability of happening to find one in such a limited sample is low. It is more likely to be a field star, be it one that apparently lies at the same distance as Praesepe, but further observations are warranted.

  The end result is therefore four probable members with proper motions (211799258, 211804579, 211990866, 211822797), one plausible member without known proper motions (211916756), one tentative member (211924657), and one probable non-member (211970234). Searches in SIMBAD indicate that EPIDs 211799258, 211990866, 211822797 and 211916756 have been identified as members in literature, which indicates good accuracy in the above results, while EPIDs 211804579, 211924657 and 211970234 have not been identified as members (and not identified at all). While the results for the M-dwarfs are not surprising seeing as they are low-confidence, that EPID 211804579 has not been mentioned is unusual since it is the second-brightest of the seven stars and an excellent match in colours and proper motion. It may be that the bright star at 10" has prevented this detection, and it looks like it may be a contaminator for the Kepler lightcurve as well.

  Ideally some spectroscopic observations could be carried out on the three new candidate members to establish whether they are bona-fide members, but this is not important for the study of their lightcurves. I will attempt to study the seven lightcurves in following comments.

  Though the results from this quite straightforward study are encouraging, there is some room for improvement. Aside from follow-up observations, it would be beneficial to invert the method - instead of searching for cluster members among planet candidates, search for planet candidates among cluster members. I have shown that it is quite possible to identify Praesepum from the EPIC plus the SDSS, and the identification of transits is naturally a well-understood process. This change in method would allow for meaningful statistics on the (transiting) planet frequency in Praesepe, which would be a very important result.

  Posted July 1, 2016 2:05 AM

• by zoo3hans in response to Shellface's comment.

  Very nice analysis Shellface! Thanks again for your effort.

  Posted July 1, 2016 8:05 AM

• by Shellface

  Thank you, zoo3hans, both for the support and for the list.

  I will be studying the cluster members in order of decreasing brightness. As all of the stars are on the main sequence this round-about equivalent to an order of decreasing temperature, as well.

  EPID 211990866: Though seemingly mundane, I suggest this is an unexpectedly significant system.

  The star is notably bright for a K2 target at V = 10.65 (Kep = 10.41), but its Johnson photometry is rather low-precision (possibly due to lying in a crowded field). The 2MASS colours give a spectral type of F8 ± 3 (~6150 ± 300 K), which is more imprecise than I would like. Huber et al., using a more proper model of the photometry, derive Teff = 5996 ± 143 K, which I opt to borrow here. I will note that the parameters derived in the Huber et al. model are not as useful, seeing as they place the star as a subgiant beyond the cluster.

  Praesepe has a fairly well established distance, though there is some inter-method discrepancies. Wang et al. adopt a cluster distance of 179 ± 2 pc, but the cluster has a much larger physical depth at about 12 pc, so I use a cluster distance of 179 ± 12 pc (parallax = 5.59 ± 0.38 mas). The cluster also has a well-established metallicity; I adopt Fe/H = 0.12 ± 0.04 dex from Boesgaard et al. (2013) (other papers give similar values). As with EPID 211311380 it is possible to perform some isochronal modelling from the available information, from which I derive M = 1.11 ± 0.05 Msol, R = 1.13 ± 0.07 Rsol, and log g = 4.35 ± 0.06 cgs. The errors are quite good, though it will be possible to improve them with more precise determinations of Teff, Fe/H and the V-band magnitude.

  Open clusters are more dense than the galactic field, so close encounters between stars is a relatively common occurrence. As the velocity difference in such encounters will be fairly low, these are very disruptive to the outer reaches of systems and result in the disassociation of wide binaries. Therefore, one would not expect to find cluster binaries that can be resolved in wide-field imaging, which remains true here seeing as there are no other stars within a considerable distance of the target. There are three stars within 1' (of which one is a cluster member), and none of them are bright or close enough to contaminate the Kepler lightcurve. Unless there is a relatively bright star very close to the star the transits must be on-target; Bouvier et al. (2001) did observe a companion at 1.03" (184 AU projected), but as it is ~6 magnitudes fainter than the primary in the 2MASS colours it may be too faint to appreciably affect the Kepler lightcurve, and if it is actually bound to the system then it would have to be so small that the transits are too long to be associated with it. Further observations are certainly warranted, but I assume that it has negligible influence on the results and that the transits are on the primary.

  The Kepler lightcurve shows a great deal of rotational variability, which is to be expected of a young star. There are a great many frequencies in the lightcurve, indicative of a large number of spots at varying latitudes, which could be used to map out the stellar surface at the time of observations. The large number of frequencies makes it difficult to give a single rotational period but it can be at least determined that it is ~4 - 5 days, which is consistent with the Praesepe rotational distribution at quite an early spectral type. This is distinct from the orbital period of 1.67 days, so the two are likely not deeply associated.

  Mermilliod et al. (2009) give a line-of-sight rotational velocity of v sin i = 13.8 ± 0.7 km/s for EPID 211990866. Since we have its radius (1.13 ± 0.07 Rsol) and rotational period (~4.5 d) it is possible to derive sin i, the sine of the inclination of the star, following this expression:

  sin i = 0.0197713... * P * (v sin i / R), where P is in days, v sin i in km/s and R in solar radii.

  Assuming a fairly conservative error on P of 0.5 days, sin i = 1.09 ± 0.23 (note that sin x > 1 is impossible, so take it as sin i > 0.86). This indicates the stellar rotational axis is fairly closely aligned to the orbital axis.

  The strong rotational variability appears to have caused some issues in processing for the Vanderburg reduction, as systematic variability is still quite evident in many parts of the lightcurve, which makes transits quite difficult to identify. I ended up only using certain transits from (BJD-2454833) 2329 to 2350, corresponding to a low level in rotational variability where systematics are correctly removed. I note that the Aigrain et al. reduction fares better, but it does show some excess variability even after removing the rotational signal altogether. Ideally a reduction with systematics removed but rotation preserved (which can be detrended to study the transits) would be possible, as I maintain that a lot about the magnetic structure can be learned from the rich set of frequencies embedded in the rotation.

  I detrended the lightcurve for the selected transits in the usual manner. For the EXOFAST input I used Teff = 5996 ± 143 K, Fe/H = 0.12 ± 0.04 dex, log g = 4.35 ± 0.06 dex and a/R = 5.43 ± 0.42 (corresponding to a density of 1.08 ± 0.25 g/cm^3, derived from the isochronal mass and radius) as priors. The following is an example output:

  

  As usual for a modest S/N transit the impact parameter is not well-constrained. The preferred value seems to be ~0.7, but models with b = 0 seem to be acceptable. If the impact parameter is low enough that δ = (r/R)^2 is valid then the companion radius is 3.49 ± 0.27 Rearth; if the impact parameter is high, this will need to be increased by a small factor.

  There seems to be some excess variability during transits, with departures of a few hundred parts per million. These may be associated with spot crossings, which would be fairly logical considering the large rotational variability. If it is indeed possible to produce a starspot map from the lightcurve, then it ought to be possible to model the transit anomalies in tandem, which would improve the transit model as well as potentially give some information on the projected obliquity of the companion.

  As I previously justified the assumption that the transits are on-target, and the transit model is consistent with a planetary companion, I will assume that the companion is indeed a planet with r = 3.49 ± 0.27 Rearth, orbiting the main star. On first impression the planet seems to be fairly mundane, as planets around ~3 Rearth are quite common. However, what I suggest makes this very special is its period, in that it is so short.

  Lundkvist et al. recently published a major paper based on the subject of atmosphere loss in hot planets. As given in the abstract, their key result is:

  …while there is an abundance of super-Earth sized exoplanets with low incident fluxes, none are found with high incident fluxes. We do not find any exoplanets with radii between 2.2 and 3.8 Earth radii with incident flux above 650 times the incident flux on Earth. This gap in the population of exoplanets is explained by evaporation of volatile elements…

  The expression for incident flux in Earth units is given as F = (ρ*)^(-2/3) * (P)^(-4/3) * (Teff)^4, where ρ* is the stellar density in solar densities, P is the orbital period in years, and Teff is in solar temperatures. For ρ* = 0.77 ± 0.18 ρ(Sol), P = 0.00458... yr and Teff = 1.038 ± 0.025 T(Sol),

  F = 1815 (+170 -384) F(Earth)

  This places the planet within the desert for all of their considered limits, though it is on the high end of the radius limit.

  The sample used by Lundkvist et al. is from Kepler, and the Kepler field is dominated by stars older than 1 Gyr. In contrast, Praesepe is 0.6 - 0.8 Gyr old (the older age being more recent, Brandt & Huang (2015)). Thus the logical conclusion is that the Kepler planets that formed in this hot sub-neptune desert have lost most-to-all of their atmospheres due to atmospheric escape processes, but this planet is young enough* that still maintains a significant volatile atmosphere. This planet is therefore extremely important for understanding atmosphere loss in very hot planets.

  *It is worth noting that it is possible that the planet arrived at its present position more recently than the cluster age if it experienced high-eccentricity migration, perhaps by Kozai oscillations due to the visual companion, though when it arrived would be difficult to determine.

  A key element to the characterisation of this planet would be mass determination. For its r = 3.49 ± 0.27 Rearth, a broad range of masses are possible; e.g. for ρ = 2.0 g/cm^3, m = 15.4 ± 3.6 Mearth, while for ρ = 0.5 g/cm^3, m = 3.9 ± 0.9 Mearth. If we assume that the planet is going to end up as a dense stripped core of radius 1.8 Rearth, then the current mass may be ~9 Mearth. Using these masses, the expected RV semi-amplitude would be ~4.5 (~1.9 - ~7.7) m/s.

  Would this be detectable? As the star is quite bright it does not look infeasible, but there are two major hurdles to consider:

  • With v sin i = 14 km/s, this is quite a fast rotator. Stellar rotation smears out lines in spectroscopy, which increases the photon noise in RVs.
  • Most importantly, this star is much more active than any normal RV target. In the study of another Praesepe star, Malavolta et al. found RV variations of around 50 m/s in semi-amplitude due to rotation, and if it similar here then activity will dominate over the planet signal.

  I can say that I am familiar with the capabilities of modern radial velocities, and it is clear to me that a mass detection here would be an impressive feat. However, I would not dismiss the possibility outright. Malavolta et al. showed that it is possible to greatly reduce the impact of rotation on RVs with careful modelling, hinging on knowledge of the spot distribution; as I have indicated, it is likely possible to build a spot map from the Kepler lightcurve, and though spot distributions vary over time the changes are modellable, Malavolta et al. showing that this is possible over a period of years with contemporaneous ground-based photometry. There are also two very good cases where weak planet signals have been identified in active stars, CoRoT-7 and Kepler-78. In both cases the rotational period is much longer than the orbital period; this is less true here (Prot/Porb ≈ 2.7), but it may still be possible to disentangle the signals.

  So, I suggest that if RV photon noise errors of ~3 m/s are possible on this star, and a dedicated observation campaign (multiple observations per night, continuous observations when possible, etc.) can be set up, a mass measurement for this planet would be viable. Such a result would be extremely important for understanding mass loss in sub-Neptunes and beyond.

  (A very recent paper from Giguere et al. showed that activity modelling in RVs is approaching the RV errors themselves, which is encouraging. Though this star is not as favourable to observe as Eps Eri, the comparison is not empty)

  It would be very interesting to see if mass loss from the planet is observable. Ehrenreich et al. observed mass loss from Gliese 436 b in the UV, where they observed a whopping 56% transit depth. Since this planet has a much higher incident flux, one would expect a much higher mass loss rate (which would also be expected if it is to lose its atmosphere on Gyr timescales), so its UV transit may be even deeper than 50%. Deriving a mass loss rate for the planetary atmosphere would be important for understanding the timescale of atmosphere loss for this sort of planet.

  Overall, this is a surprisingly interesting system, exemplary of the unique observational environments that open clusters provide. Undoubtedly a difficult target, I hope that useful results can be obtained in the near future.

  Posted July 4, 2016 12:17 AM

• by Shellface

  EPID 211804579:

  As previously noted, there is a relatively bright star at 10" (see also page 13). It is about 2 magnitudes fainter than the target in the Kepler band, which translates to a 1 : 0.15 brightness ratio. It is much bluer than EPID 211804579 (spt ~F1), so it cannot be a member of Praesepe. I expect the star is far in the background (the high proper motions are likely in error).

  At a separation of 10" this star is not well resolved by Kepler, and it can be observed that the two stars overlap in the Kepler pixel map. It is therefore probable that the nearby star significantly contributes to the Kepler lightcurve.

  In the lightcurve plot on the above-linked page, variations in transit depth are identifiable by the eye: from the start of the lightcurve the transits are 0.03% - 0.06% deep, which grows to about 0.08% at mBJD ~ 2330, and then again to ~0.10% after mBJD ~ 2345. Such large depth changes are unlikely to be physical, as the transit does not have the profile of a disintegrating planet. They are also unlikely to be due to dilution of transits on EPID 211804579 by the nearby star due to the large amplitude of variation, so they are most likely associated with the nearby star. Therefore, this is probably a case of EB contamination.

  Posted July 5, 2016 5:15 PM

• by Shellface

  EPID 211924657: This is the brightest of the surviving late-type stars. However, it turns out that the star is not a cluster member:

  • In the J-band sequence the star lies just above the confirmed Praesepis EPID 211822797, but in the P1 sequence it is considerably fainter than EPID 211822797. This clearly indicates the star is a redder foreground star, but I did not interpret this evidence correctly.
  • The star has a spectral type of ~M3.5, which is later than expected for its brightness if considered a cluster member (EPID 211822797 has a spectral type of~M0). This supports the placement of the star in the foreground.
  • The star has a proper motion measurement in the SDSS, though I am not certain of the source. It is given as 129.00 ± 4.12 mas/yr at angle -172.88°; this is a fairly old-fashioned notation, and transforms into the modern notation via sine and cosine into PM(RA) = -16.0 mas/yr, PM(dec) = -128.0 mas/yr. These are very different to the cluster motions and firmly exclude it as a member. The overall motion is also several times faster than the cluster, which supports its location in the foreground.

  Thus I consider the star to be a foreground M-dwarf from here on. Based on its brightness, its distance is perhaps 75 ± 15 pc.

  EPID 211924657 is a faint star at Kepmag = 15.03, but it surprisingly has Johnson magnitudes of B = 17.873 ± 0.170 mag and V = 16.248 ± 0.072 mag. The errors are quite large, but due to the fast changes in colour in late-type stars this gives a reasonably good constraint in spectral type, M4 (+1 -6). The 2MASS J-H has a better precision at 0.578 ± 0.039, but this is degenerate between spectral types of ~K5 and ~M4 due to a turn-over in the J-H curve for dwarfs. In this case the V-K index is very useful, as its value of 4.878 ± 0.095 unambiguously places the spectral type of the star as M3.5 ± ~0.5 (Teff = 3300 ± 100 K).

  This is slightly cooler than found by Huber et al. at 3466 ± 100 K, but as their other parameters are off as well, this is likely not a serious discrepancy. Another temperature is listed on K2FOP, from an SED fit, which gives 3300 ± 50 K. Inspection of the values given for other stars indicate the temperatures found by this technique suggest their temperatures are mostly accurate (particularly for cooler stars), but their values for log g are not - unsurprising, as the effects of density on colour are very subtle. I am not certain that their error bound is representative, though, so I stick with Teff = 3300 ± 100 K.

  No other stars appear within in 20" in 2MASS or the EPIC, and no bright stars appear for some distance. However, Edd does note a very faint star at ~4.5". It is quite red, so it is worth considering whether it could be bound to EPID 211924657. I recovered the faint star in the SDSS DR12, and found it to be ~6 magnitudes fainter than the target in the 5 bands. I do not have any temperature calibrations for the SDSS indices, but the PAN-STARRS transformations used above result in similar colours for both stars, with g (P1) - y (P1) = 3.347 ± 0.011 and 3.39 ± 0.36 respectively. It appears that the star is also an M-dwarf, but far in the background.

  If the 6.2-magnitude difference in the SDSS bands for the two stars are diagnostic for the Kepler band (which it should be, considering the similar colours), then the faint star should contribute ~0.3% of the flux in the lighcurve. It thus cannot be the source of the 0.5% deep transits, and cannot have any meaningful effect on the lightcurve. Unless there is a very close companion the transits must be on-target, and I will assume that this is true from here.

  The Kepler lightcurve shows no major rotational variability, which contrasts with the clear rotational signals observed in all of the Praesepe members. This is consistent with cluster non-membership for the star, and indicates it may be quite old.

  I could not find an orbital period that produces a good transit profile, which is a first for the K2 objects I have looked at. The same issue appears in the plots by aja, in which most transits appear to match but some occur a few hours late (pages 14 and 16: I assume this merely human error, as with Edd's responses on pages 15 and 17, but the repetition is rather comical), so it appears this is not my mistake. It does not appear to be a systematic issue, as though the transits are fairly short they clearly do not align to a single ephemeris. It thus seems that this system exhibits TTVs, as noted by zoo3hans in his list, which is very uncommon for K2 systems.

  To measure the transit times I used the same method as I did for KOI-134. In this case the transits are much shorter and only ever contain a handful of LC points, so it is possible that the errors may be underestimated due to overfitting - this appears to be true, as the transits with the least datapoints have the smallest errors. I thus assume a constant error on the transit times of 0.002 days (~3 mins), about twice the mean statistical error. The lack of transit data also make individual measurements of the transit duration too imprecise to be useful.

  The resulting transit times are given below:
  transit number | time (BJD - 2454833) (d) | error (d)

  1 2309.003149 0.002 11 2335.438678 0.002 20 2359.233431 0.002

  2 2311.646586 0.002 12 2338.086679 0.002 21 2361.883401 0.002

  3 2314.298377 0.002 13 2340.726312 0.002 22 2364.532082 0.002

  5 2319.583082 0.002 14 2343.371913 0.002 23 2367.185826 0.002

  6 2322.222289 0.002 16 2348.662627 0.002 24 2369.826189 0.002

  7 2324.869328 0.002 17 2351.304915 0.002 25 2372.483078 0.002

  8 2327.511984 0.002 18 2353.945483 0.002 26 2375.133549 0.002

  10 2332.795091 0.002 19 2356.597846 0.002 27 2377.786021 0.002

  The missed transits (4, 9, 15) are either over-corrected or only contain one in-transit point.

  The transit time residuals, computed with P = 2.6464 days, are shown below:

  

  With a semi-amplitude of ~0.025 days, the TTVs are highly significant. They appear to show no more than 3/4s of a super-period, which indicates P(TTV) > 90 d. There also appears to be some high-frequency variability above the errors, which may be due to chopping.

  The TTV signal is not adequately sampled in phase. Only one extrema is well-covered, though it appears that the start of the data may cover part of another extrema. Because of this there is a degeneracy between orbital period and TTV amplitude + TTV period, which make it difficult to provide predictive ephemerides. There is therefore a real possibility that the transits may become "lost" (unrecoverable) unless additional transit times can be secured in the near future, because the degeneracy creates an uncertainty that increases over time.

  The degeneracy also makes study of the TTVs difficult, seeing as amplitude and period are the only two observables. I will not attempt to properly study the TTVs, though I note that preliminary calculations with the nominal parameters suggest the mass of the perturber is within ~1 order of a Jupiter mass. Considering that the implied outer period is < 10 days this is quite unusual, as such planets are very rare around M-dwarfs. It is a shame that the outer companion is not transiting.

  EXOFAST cannot model variable transit times, so to model the transits I adjusted the times of observations so that they follow a single ephemeris. While this works effectively, do note that the transit time is not the real transit time, and also that the period is forced to a particular value (here 2.6464 days) that also may not be representative of reality.

  EXOFAST is also not calibrated to model stars cooler than 3500 K. This does not directly affect the transit model, but it significantly affects the modelled stellar parameters, and thus the companion radius. Thus, please do not take the strange stellar parameters given below as gospel.

  

  The transits are well-formed, with decent S/N (~10 times photon noise). The transits are only ~1.3 hours long, so they are not greatly resolved compared to the 0.49-hour LC integration time. Still, a low impact parameter seems to be preferred (which suggests a non-negligible mutual inclination with the outer companion).

  What are some more realistic stellar parameters? As previously established, the spectral type of the star is M3.5 ± ~0.5 (Teff = 3300 ± 100 K). M3 and M4 are quite widely spaced in physical parameters, with the stellar mass going from ~0.40 Msol to ~0.20 Msol. For non-extreme metallicities one would expect a mass of ~0.30 Msol and as M ≈ R for M-dwarfs, then R ≈ 0.30 Rsol. If R = 0.30 ± 0.10 Rsol is assumed, then r = 2.04 ± 0.68 Rearth. A better constraint would be possible with follow-up observations, but this is provisionally compatible with a sub-neptune.

  In terms of further observations, recovery of the transit ephemerides is most important. Due to the large amplitude of variations only a couple of transit times with <1 hour precision, separated by a few weeks, would be enough to solve the previously discussed degeneracy and give predictive ephemerides. I estimate a timing uncertainty of no more than 3 hours at the current date, but this will get worse over time.

  As the star is very faint in the visible bands, this is outside of feasibility of amateur observations. Professional telescopes, ground-based or space-based, are necessary. As an M-dwarf the star is proportionally bright in the infrared bands, observations with Spitzer are likely the most viable for transit recovery.

  With a large amplitude and likely short period, there is a good possibility that the TTVs would be solvable. If the perturber really is massive, it may be detectable in RVs despite the extreme faintness of the star, but I suggest a decent mass constraint from TTVs should be sought first as it is possible that a Jovian mass is an overestimate.

  Though not a cluster member, this happens to be a very interesting object in its own right. Despite being extremely faint, it does appear to be a system of scientific value, so hopefully some further observations may be mustered.

  Posted July 6, 2016 11:39 PM

• by Shellface

  EPID 211822797:

  This star has excellent photometric coverage considering it is so faint (V = 15.26, Kep = 14.57). From this I derive a spectral type of M0 ± <0.5 (Teff = 3800 ± ~50 K). This agrees very well with the Huber et al. Teff = 3826 ± 92 K, though it is slightly different to the SED value on K2FOP at Teff = 3900 ± 50 K. Provisionally I adopt the same value with a slightly inflated error, i.e 3800 ± 75 K.

  Isochrones are not calibrated to as great a certainty for late-type stars, but I attempted an isochrone fit with the Praesepe parameters, which resulted in M = 0.553 ± 0.009 Msol and R = 0.493 ± 0.011 Rsol. The errors are likely too small and the result seems a little too dense, but they are not unreasonable. For comparison I calculated the radius directly from the Stefan-Boltzmann Law, which results in R = 0.57 ± 0.04 Rsol - though there is likely some systematic error, as I am uncertain on the validity of the bolometric correction I used. The values do disagree somewhat, so I assume an intermediate value of 0.53 ± 0.05 Rsol.

  Edd identified a nearby star on page 14. It is very faint so it only appears in a few catalogues, and again quite red. Comparing its SDSS magnitudes (link) to those of the target (link) indicate they have differing spectral types, but I do not have calibrations for the SDSS bands. I managed for retrieve its JHK magnitudes from UKIDSS: they are J = 17.865 ± 0.055, H = 17.375 ± 0.052, and K = 17.079 ± 0.061. Owing to the faintness these are weak and do not provide good constraints on the spectral type, Which is consistent with most of M.

  The magnitude differences between the stars would imply a spectral type of L0 for the nearby star if they lay at the same distance, which is mildly inconsistent with the colours. Thus I conclude that the star is more likely a background M-dwarf, but it is not entirely impossible that it is bound. Imaging observations may be necessary to reach a final conclusion. Regardless, because it is so much fainter than the target (~6 magnitudes) the transits would have to be due to a high radius ratio EB if they were associated with the fainter star, which is inconsistent with their shape. Hence I assume that the transits are on the brighter star.

  The out-of-transit lightcurve shows significant activity, though it is difficult to place its period. This is compatible with a Praesepe age for the star.

  I detrended the transits as usual. Four transits occur during the Kepler observations but one (2353.75) is over-corrected and as a result "lost", so only three transits are used in the EXOFAST model. With input priors of Teff = 3800 ± 75 K and Fe/H = 0.12 ± 0.04, the transit model is shown below:

  

  The transit duration is quite long considering the late-type host star, so for circular orbits the impact parameter is forced to be low in order to keep the stellar density sensible.

  For R = 0.53 ± 0.05 Rsol, r = 2.31 ± 0.22 Rearth, which suggests the companion is a small sub-neptune. Due to the late-type host the companion is relatively cool, though it is certainly interior to the habitable zone.

  Kepler has shown that systems like this are fairly common, so there is not much more to be said on its nature. The star is not much brighter than a Kepler M-dwarf, but it has the added element of a known age (which is usually difficult for M-dwarfs). While the companion is not currently a viable target for a mass measurement, it should be a straightforward target for statistical validation.

  Posted July 7, 2016 10:03 PM

• by Artman40

  http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?objname=HIP+41378+b&type=CONFIRMED_PLANET

  HIP+41378 and its planet candidates are now confirmed, despite most of them having only a single transit. K2 name of the host Star is K2-93. This means we can expect a lot of planets in the future.

  Posted July 8, 2016 7:02 PM

• by Shellface

  EPID 211799258:

  This star is too faint to have Johnson magnitudes (Kep = 15.98), so I am forced to use only the 2MASS colours to type the star. Due to the turnover in J-H it cannot be used to unambiguously locate the star, so only H-K can be used. This gives M2 ± 3, which is too weak to really be useful. I therefore turn to the SED Teff listed on K2FOP, 3300 ± 50 K (~M3.5). In the Wang et al. sequences the star lies just below the 0.29 Msol point, which is consistent with this Teff. I thus adopt this value, though as I am still uncertain on the accuracy of the error margins I inflate it to 3300 ± 100 K (M3.5 ± 0.5).

  Edd has once again pointed out a nearby star, at about 5" separation. As far as I can tell it is only really recorded in the SDSS, in which it appears to be ~6 magnitudes fainter than the target. The magnitude difference appears to increase towards redder wavelengths, and as the SDSS bands are bluer than the peak wavelength of M-dwarfs this suggests the star is redder than the target, though I cannot tell how much. If the objects are equidistant then the faint star would have to be a brown dwarf, but it seems unlikely that a low-mass binary with separation >500 AU could survive in the dense environment of Praesepe for so long. Further observations will be necessary to make judgements on the nature of the faint object, but as it is >100 times fainter than the target it cannot meaningfully affect the Kepler photometry, particularly the deep transits.

  The out-of-transit lightcurve shows rotational variability at the 1.5-2.0% level, with a rotational period of either ~24 or ~50 days. This is a fairly short rotational period for a mid-M dwarf, and is compatible with Praesepe membership. Additionally, several flares are present in the lightcurve. The two largest flares are shown below:

  

  I count four resolved flares, with heights in excess of 2%. In addition, there are countless positive bumps in the lightcurve consisting of only one or two points. Since there are no accompanying negative bumps these do not appear to be systematic in nature, so it seems reasonable to assume these represent smaller flares. They appear to have heights ranging from 3% down towards the detection limit, perhaps a few tenths of a percent. I am not very familiar with the topic, but the largest flares present may fall into the definition of superflares.

  Four transits are present in the lightcurve. With a depth in excess of 6% these are very deep - deeper than the 5% rule-of-thumb I have referred to previously - but the exceptionally small host star means they are not necessarily stellar in nature.

  I detrended the transit lightcurve for modelling. Again, the star is cooler than the limit for EXOFAST, so do not take the (very) strange stellar parameters at face value.

  

  Due to the small number of in-transit datapoints and the poor resolution of much of the transit (especially the minimum), this model is extremely susceptible to overfitting and other accumulative errors. I will attempt to note regions of caution:

  • The limb darkening coefficients are most likely wrong. These values are close to the solar ones, yet for a mid-M dwarf they should be more severe. Because the transit features are barely resolved it is difficult to say what effect this has on the fit, but I can guess that the impact parameter is overestimated.
  • The fitted depth appears to be reasonable, so I have not "corrected" it. However, the transit centre does not actually have coverage and non-negligible integration times complicate direct calculation of depth, so this value should be taken as a guess. Plausible transit depths are probably confined to the range [0.07, 0.10], which to first-order expression indicates r/R = [0.26, 0.32].
  • All of the error terms are undoubtedly overfitted, so their low errors are not representative.

  In spite of all this, it is worth noting that the fitted stellar density appears to be real. From the spectral type one would expect a density of about 19 g/cm^3, while the fitted value is 89 g/cm^3. Though the impact parameter may be overestimated, increasing impact parameter actually decreases apparent density, so the discrepancy may be understated. With such little information on the real transit parameters it is beyond my ability to say why, but the simplest explanation would be a combination of high impact parameter and eccentricity. It is also possible that the poor quality of this fit is exacerbating the issue by some means.

  For a crude estimate of R = 0.27 ± 0.05 Rsol, then for r/R = [0.26, 0.32], r = [6.2, 11.2] Rearth to first order (no second-order effects on transit depth). Most of the error actually comes from the error on R, despite the very uncertain transit depth. This is broadly compatible with a giant planet, brown dwarf or very-low-mass star, and it is beyond the capabilities of photometry to discriminate between the possibilities.

  It would be very important to obtain further transit observations to properly model the system. Though the star is extremely faint the large depth means transit observations from the ground are viable, though they will likely require professional telescopes. As the star is brighter in the infrared observation with Spitzer would be ideal.

  It is worth noting that the companion receives an insolation comparable to Earth. I estimate an incident flux of 0.9 ± 0.3 F(Earth), most of the error coming from the weakly constrained stellar density. Though certainly too large to be terrestrial the usual argument for such giant planets is that their hypothetical moons may be habitable, so it could be construed that this system is potentially habitable. This would make it the first such system in any cluster, though it is a bit of a stretch. I would also hesitate to consider a violent flare star as habitable real estate, but that is another matter.

  Overall this is a difficult target, perhaps more for my (inefficient) methodology than in general. The companion (if planetary) may represent a very rare type, as giant planets around M-dwarfs are uncommon and difficult to detect by transit. Hopefully some workable results can be gained from the Kepler lightcurve.

  Posted July 11, 2016 9:33 PM

• by Shellface

  EPID 211916756:

  Again, this star is too faint to have good photometry (Kep = 15.50), so I adopt the SED value with inflated error at 3400 ± 100 K (M3 ± 0.5)

  The position of the star on the Praesepe sequence does stand out somewhat. It is about 0.3 magnitudes fainter than EPID 211799258 in the J-band, but they are equal in the g(P1)-band. This indicates this star is bluer, which is observed in the second sequence. This leads to its position 0.3 magnitudes below the sequence in the g(P1) band. I estimate this translates to a distance ~25 pc beyond the cluster centre at 179 pc, which is beyond the tidal radius (12 pc).

  The star definitely shares the cluster proper motions (-36, -7 mas/yr), and its rotational period found below indicates a Praesepe-like age, so it does appear to be a Praesepis. Assuming it truly is a cluster member there are two remaining options to explain its faintness, either the star has actually been evaporated from the cluster or that there are non-negligible errors in its position on the sequence (the statistical errors are small, so they would have to be systematic). The latter is more likely a priori, but the issue is worth a more definitive investigation. Regardless, this does not have much bearing on the transit modelling.

  For once, there appear to be no nearby stars. Nothing appears within half an arcminute in 2MASS or the EPIC, and a note in K2FOP shows no stars are detected within 1". It seems reasonable to assume that third light is negligible.

  The out-of-transit lightcurve reveals a rotational period of ~25 days with several harmonics. This is around expectations for a Praesepe M3 dwarf, and supports the association of the star to the cluster. There also appear to be a number of flares in the lightcurve, though none of them are resolved into more than 2 points. The largest reaches a height of ~5.5%.

  I detrended the transit lightcurve in the usual manner. The first transit occurs close to the start of the lightcurve and is partially skewed by systematics, so only the latter half is included in the fit. Once again, note that the following stellar parameters are likely not accurate:

  

  Though the S/N of the transits is relatively poor (depth/rms = 8.1), the overall shape is well-resolved. The low impact parameter appears to be real, though the exact value is likely influenced by the incorrect stellar parameters. The short transit duration matches an M-dwarf host rather nicely.

  The value of r/R is 0.0854 ± 0.012 and I estimate R to be 0.39 ± 0.06 Rsol, so r = 3.64 ± 1.07 Rearth. The large fractional error on r stems from the photon noise (~1000 ppm) and the large fractional error on R, both of which will be difficult to improve upon. Still, it appears that the companion is a roughly Neptune-sized object at a fairly low insolation.

  As with EPID 211822797 there is not much more to be said, seeing as this would be a fairly normal planet. Despite its faintness, validation should be viable for this system.

  Posted July 15, 2016 4:51 PM

• by Shellface

  Yesterday there was a K2 paper on arXiv on the topic of Praesepe:

  A PSF-based approach to Kepler/K2 data. II. Exoplanet candidates in Praesepe (M 44)

  In this work we keep pushing K2 data to a high photometric precision, close to that of the Kepler main mission, using a PSF-based, neighbour-subtraction technique, which also overcome the dilution effects in crowded environments. We analyse the open cluster M 44 (NGC 2632), observed during the K2 Campaign 5, and extract light curves of stars imaged on module 14, where most of the cluster lies. We present two candidate exoplanets hosted by cluster members and five by field stars. As a by-product of our investigation, we find 1680 eclipsing binaries and variable stars, 1071 of which are new discoveries. Among them, we report the presence of a heartbeat binary star. Together with this work, we release to the community a catalogue with the variable stars and the candidate exoplanets found, as well as all our raw and detrended light curves.

  Module 14 contains the core of Praesepe and the half-mass radius. As many of the low-mass stars lie further out than this (Praesepe being significantly mass-segregated), many of the M-dwarfs are not included.

  The authors find seven planet candidates, and identify two of them as cluster members; these are EPIC 211913977 and EPIC 211916756. Additionally, they identify two planet candidates from Pope et al. in module 14 as cluster members; these are EPIC 211969807 and EPIC 211990866.

  EPIC 211916756 and EPIC 211990866 were identified in my work. Our results are broadly similar, though they use the Huber et al. parameters which are incorrect for both stars. In both cases they find a smaller transit depth, and this appears to apply for all of their results, so I suspect there is some issue in the processing.

  I did not identify EPIC 211913977 and EPIC 211969807, which is because they were not identified on Planet Hunters. For EPIC 211913977 the transits are unidentifiable due to the much larger rotational variability, though they become quite obvious with the rotation removed (observe). This shows an important merit in using the plots produced by Vanderburg, at least for strong rotators. In the case of EPIC 211969807 the transits are entirely unidentifiable to the eye (observe); I am not entirely convinced they are real, but either way the issue is that they are too weak to be found by inspection, which is where computational methods have a clear advantage.

  The remaining Praesepe planet candidates identified here but not in this paper (EPIC 211822797, EPIC 211799258) lie outside of module 14. The false positive EPIC 211804579 is not identified as it also lies outside the module, though it may or may not have been identified as a planet candidate had it been included. The cluster non-member EPIC 211924657 is also correctly identified, though its TTVs are not.

  I expect there may be a small number of Praesepe planet candidates (perhaps 1 - 2) that have still not been noticed, given that the bright EPIC 211913977 was not found here. The Praesepe K2 yield seems to be around 4 - 7 planets, though some work remains before the final count can be established.

  Posted August 3, 2016 1:33 AM

• by zoo3hans in response to ajamyajax's comment.

  EPIC 211391664 is now confirmed as a Neptune-sized planet in http://arxiv.org/abs/1608.01165

  Posted August 4, 2016 8:33 AM

• by Artman40

  http://arxiv.org/abs/1608.04760

  "An Unusual Transiting Neptune Found in the Beehive Cluster"

  A neptune-sized planet in ~10-day period found around M3 dwarf.

  Posted August 18, 2016 3:51 AM

• by Artman40

  http://arxiv.org/abs/1608.08539

  Checking whether candidates found in Messier 67 match what was found in that paper.

  Posted August 31, 2016 4:57 AM

• by zoo3hans in response to Martti_Holst_Kristiansen's comment.

  EPIC 211413752 seems to be confirmed in http://arxiv.org/pdf/1608.08539v1.pdf

  Posted August 31, 2016 9:05 PM

• by Shellface

  Zodiacal Exoplanets in Time (ZEIT) IV: seven transiting planets in the Praesepe cluster

  …We identify seven planet candidates, six of which we statistically validate to be real planets.…

  Close enough.

  All the different works on Praesepe are getting rather confusing, so here is a quick table of the planets and planet candidates:

  

  bold text + grey shading indicates the planet was validated in that work. This paper has validated all previously identified planets (PH or literature) except the difficult EPIC 211799258. In cases where we overlap my results agree, and the other results seem reasonable.

  A striking new detection is EPIC 211970147, a K3.5 dwarf with a 1.3 Rearth planet on a 9.92-day orbit. The transits are only just barely discernible by eye, so it is not surprising they went undetected here. This indicates that K2 can detect terrestrial planets around K-dwarfs even on relatively long-period orbits, given ~100 ppm per-point precision (achievable for Kp ~< 13)

  Though some note is given to the large radius of K2-95b (EPIC 211916756 b) for a mid-M dwarf, the large radius of EPIC 211990866 b for such a hot planet is not. The radius in the paper is 3.5 ± 0.2 Rearth, and recalculating its incident flux from the published parameters,

  F = 2097 (+80 -69) F(Earth)

  This is even higher than my previous calculation (1815 (+170 -384) F(Earth)), and as the planetary radius is almost identical to my previous value the planet is firmly within the desert identified by Lundkvist et al.

  If I may reiterate my previous conclusion:

  The sample used by Lundkvist et al. is from Kepler, and the Kepler field is dominated by stars older than 1 Gyr. In contrast, Praesepe is 0.6 - 0.8 Gyr old (the older age being more recent, Brandt & Huang (2015)). Thus the logical conclusion is that the Kepler planets that formed in this hot sub-neptune desert have lost most-to-all of their atmospheres due to atmospheric escape processes, but this planet is young enough* that still maintains a significant volatile atmosphere. This planet is therefore extremely important for understanding atmosphere loss in very hot planets.

  *It is worth noting that it is possible that the planet arrived at its present position more recently than the cluster age if it experienced high-eccentricity migration, perhaps by Kozai oscillations due to the visual companion, though when it arrived would be difficult to determine.

  There are two points to add here. First, imaging described in this paper re-detect the stellar companion, with a similar position angle and separation to Bouvier et al. As the observations are displaced by ~18 years and the star's proper motion is 36 mas/yr, the two stars must be co-moving to have maintained the same relative positions. While it is possible that the other star is merely another cluster member rather than bound to EPIC 211990866, it is relatively unlikely to find two cluster members separated by only 1", so it is more likely they are actually bound at a projected separation of ~180 AU. Second, this paper finds slight evidence of planetary eccentricity (e = 0.24 (+0.19 -0.12)), which would support a recent deposition of the planet into its current orbit. This measurement can be improved upon by better resolution of the ingress egress to improve the precision on the impact parameter (feasible, considering V = 10.7), and a better constraint on the stellar density (difficult)

  I advocate further study of this planet - it offers an excellent test case for the study of atmospheric and orbital evolution in a highly irradiated low-mass planet.

  Posted September 6, 2016 6:29 PM

• by zoo3hans in response to ajamyajax's comment.

  EPIC 211525389 is now confirmed as a planet in https://arxiv.org/abs/1701.01294

  Posted January 6, 2017 4:52 PM

• by Artman40

  https://arxiv.org/pdf/1702.05488.pdf

  A a new EVEREST 2.0 light curve pipeline has been created for K2 campaigns 0 to 8 that's freely available.

  It improves the photometric precision compared to EVEREST 1.0 by 10-20%. The improvement is more noticeable on fainter stars. Photometric precision is at near original Kepler level in campaigns 1, 5 and 6 for stars up to magnitude 15 and up to magnitude 13-14.5 for most other campaigns.

  The new data also has less overfitting errors, meaning that some eclipses and transits that EVEREST 1.0 pipeline mistakenly removed are now present.

  Finally, the new pipeline has better data correction during K2's thruster firing events, adding usable 100-300 new data points per target, depending on campaign. For long-cadence targets, that means about extra 2-6 days worth of data spread throughout the time a target was observed.

  https://archive.stsci.edu/prepds/everest/

  Posted February 24, 2017 1:53 PM

• by zoo3hans in response to Artman40's comment.

  Thanks Artman40, it seems to work well. For example for EPIC 211525389 :

  

  Posted February 25, 2017 9:01 AM

• by Artman40

  Interesting. 21.64 ppm is original Kepler level. How does it compared to the older one?

  Also, do improved light curves help to confirm some of the current K2 planet candidates?

  Also, calibrated campaign 11 data release has been delayed to mid-April. Seems that Kepler science center has not adjusted data release dates in future campaigns either.

  Posted February 25, 2017 10:50 AM

• by zoo3hans in response to Artman40's comment.

  I don't have everest 1.0 data, but Vanderburg's corrected LC looks like this: 31.2 ppm

  

  Posted February 25, 2017 11:45 AM

• by zoo3hans in response to Artman40's comment.

  And yes, I hope that the improved LC's do help support our planet claims. I add a few images below (some are already confirmed planets though):

  epic_211311380
  

  epic_211351816
  

  epic_211355342
  

  epic_211391664
  

  epic_211413752
  

  Posted February 25, 2017 11:58 AM

• by zoo3hans in response to Artman40's comment.

  epic_211579683
  

  epic_211770696
  

  epic_211770795
  

  epic_211822797
  

  epic_211906650
  

  Posted February 25, 2017 12:18 PM

• by zoo3hans in response to Artman40's comment.

  epic_211916756
  

  epic_211924657
  

  epic_211939692
  

  epic_211990866
  

  epic_212006344
  

  Posted February 25, 2017 12:25 PM

• by zoo3hans in response to Artman40's comment.

  epic_212069861
  

  epic_212130773
  

  Posted February 25, 2017 12:28 PM

• by Artman40

  Very interesting. Are other campaigns also re-examined with this new dataset?

  Posted February 26, 2017 10:13 AM

• by zoo3hans

  As you have written yourself, C0-C8 have been reprocessed. I could post other plots if you wish. Just tell me the desired EPIC's.

  Posted February 26, 2017 12:28 PM

• by zoo3hans

  Ok, in any case here you go with a few other candidates (from page 1 of this thread) where I think the Everest data does support our case:

  epic_211331236
  

  epic_211319617
  

  epic_211351816
  

  epic_211359660
  

  epic_211399359
  

  Posted February 26, 2017 4:55 PM

• by zoo3hans

  epic_211401787
  

  epic_211418290
  

  epic_211418729
  

  epic_211432167
  

  epic_211490999
  

  Posted February 26, 2017 4:59 PM

• by zoo3hans

  epic_211503363
  

  epic_211505089
  

  epic_211509553
  

  epic_211529065
  

  epic_211562654 (multi planet system)
  

  Posted February 26, 2017 5:07 PM

• by zoo3hans

  epic_211578235
  

  epic_211579112
  

  epic_211594205
  

  epic_211606790
  

  zoom into the above LC:
  

  epic_211611158
  

  Posted February 26, 2017 5:15 PM

• by zoo3hans

  epic_211680698
  

  epic_211713099
  

  epic_211736671
  

  epic_211763214
  

  epic_211765775
  

  Posted February 26, 2017 5:22 PM

• by zoo3hans

  epic_211770867 (probably EB)
  

  epic_211791178
  

  epic_211798340
  

  epic_211816003
  

  epic_211818569
  

  epic_211825799
  

  Posted February 26, 2017 5:28 PM

• by zoo3hans

  epic_211919004
  

  epic_211923431
  

  epic_211929937
  

  epic_211988320
  

  epic_211993818
  

  Posted February 27, 2017 7:31 PM

• by zoo3hans

  epic_212008766
  

  epic_212099230
  

  epic_212110888
  

  epic_212132195
  

  epic_212138198
  

  Posted February 27, 2017 7:40 PM

• by zoo3hans

  And the last batch for C5:

  epic_212152341
  

  epic_212154564
  

  epic_212157262
  

  epic_212164470
  

  Posted February 27, 2017 7:44 PM

• by zoo3hans in response to ajamyajax's comment.

  EPIC 211331236 both planet candidates are now validated in https://arxiv.org/abs/1703.07416

  P1 = 1.292 days

  P2 = 5.444 days

  Posted March 23, 2017 8:44 AM

• by zoo3hans in response to Shellface's comment.

  EPIC 211916756 is now confirmed as a Neptun sized planet in http://iopscience.iop.org/article/10.3847/1538-3881/aa62ab/meta;jsessionid=B1C1A6182B974C3A3B7C41367D09038D.c1.iopscience.cld.iop.org

  Posted March 28, 2017 9:49 PM

• by Shellface in response to zoo3hans's comment.

  Curiously, this is the third time this planet has been validated by independent groups ([1] [2]). I would guess this new paper got a delayed publication, since the abstract is written as if it was from before Obermeier et al. was published last August.

  Posted March 29, 2017 10:51 PM

• by Artman40

  https://archive.stsci.edu/k2/

  The Campaign 18 Raw cadence data is now online.

  Posted August 7, 2018 3:56 PM