Planet Hunters Talk

EPIC 205519771

  • davidbundy77 by davidbundy77

    There seem to be numerous transit-like drops with nice u-shapes, but no obvious periodicity. The depths also differ considerably. Any ideas what is going on here?

    Posted

  • ajamyajax by ajamyajax in response to davidbundy77's comment.

    Re: 205519771: I don't know, but the Planet Hunters science team and friends just published a paper on a similar-looking LC perhaps, so you might contact them and see what they think.

    EPIC 205519771:

    K2 target

    KIC 8462852:

    K1 target

    http://oldtalk.planethunters.org/objects/APH10115382/discussions/DPH101e830

    "Planet Hunters X. KIC 8462852 - Where's the Flux?"
    T. S. Boyajian, D. M. LaCourse, S. A. Rappaport, D. Fabrycky, D. A. Fischer, D. Gandolfi, G. M. Kennedy, M. C. Liu, A. Moor, K. Olah, K. Vida, M. C. Wyatt, W. M. J. Best, F. Ciesla, B. Csak, T. J. Dupuy, G. Handler, K. Heng, H. Korhonen, J. Kovacs, T. Kozakis, L. Kriskovics, J. R. Schmitt, Gy. Szabo, R. Szabo, J. Wang, S. Goodman, A. Hoekstra, K. J. Jek

    http://arxiv.org/abs/1509.03622

    Posted

  • Dolorous_Edd by Dolorous_Edd

    Just for the hell of it

    https://www.cfa.harvard.edu/~avanderb/k2c2/ep205519771.html

    And

    UKIDSS-K band

    enter image description here

    SDSS J160714.01-170242.7

    enter image description here

    Posted

  • ajamyajax by ajamyajax in response to Dolorous Edd's comment.

    And 205519771 could be a cool M-dwarf with a Teff < 3200K, which at a glance at the NEA data appears to differ quite a bit from KIC 8462852.

    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)

    205519771 , 2MASS J16071403-1702425 , 11.754 , 11.045 , 10.754 , 0.709 , 0.291 , ('M8V', 0.082) , ('M4V', 0.24)

    Posted

  • Martti_Holst_Kristiansen by Martti_Holst_Kristiansen

    Earlier this summer I contacted Tabetha concerning these K2 C2 phenomenons. They are T-Tauri systems (dippers), and additional examples can be seen in this post: http://talk.planethunters.org/#/boards/BPH0000007/discussions/DPH0000bhy (page 3, post 2 & 7).

    Perhaps this paper could be useful: http://arxiv.org/pdf/1401.6582.pdf

    Posted

  • Shellface by Shellface

    Adding to what Martti said - the star is a member of the Upper Scorpius association, which is only a few million years old. At such a young age, stars in the association are quite likely to be actively accreting material from the inner edge of its proto-planetary disk, which is observed in the lightcurve - the dips are presumably due to the crossings of clumps of material.

    The phenomena are similar, but the KIC star is likely transited by comets, which have different orbital parameters to proto-planetary disk material - longer orbits with high eccentricities. The actual transits, however, are quite comparable.

    Posted

  • davidbundy77 by davidbundy77

    Thank you for all your fascinating responses!

    Posted

  • ajamyajax by ajamyajax

    As seen on PH, 204449274 could be another of these. Upper Sco Young Star per the archive. It's a bit different. Maybe more blended.

    http://talk.planethunters.org/#/subjects/APH0000ixr

    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)

    204449274 , 2MASS J16222160-2217307 , 13.742 , 13.090 , 12.617 , 0.652 , 0.473 , ('M7V', 0.098) , ('M8V', 0.082)

    And listed as QP, P=1.548 only on the newer EB search page:

    K2VARCAT Data Search & Retrieval

    https://archive.stsci.edu/k2/hlsp/k2varcat/search.php

    T1

    (Update) 203806628: maybe another one here.

    203806628 , 2MASS J16271513-2451388 , 10.619 , 9.774 , 9.392 , 0.845 , 0.382 , ('L1V', '...') , ('M6V', 0.1)

    http://talk.planethunters.org/#/subjects/APH0000grp

    'rho Oph/Upper Sco' per the archive.

    Posted

  • ajamyajax by ajamyajax

    Re: 204472612 per Hans Martin, maybe a young T-Tauri star:

    http://talk.planethunters.org/#/subjects/APH0000j1m

    Also listed as '2056 (Upper Sco Young Star)' on K2VARCAT.

    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)

    204472612 , 2MASS J16083455-2211559 , 12.559 , 11.931 , 11.530 , 0.628 , 0.401 , ('K7V', 0.64) , ('M7V', 0.098)

    T1

    Posted

  • ajamyajax by ajamyajax

    EPIC 203410665 from Martti Holst Kristiansen's C2 list:

    http://talk.planethunters.org/#/boards/BPH0000007/discussions/DPH0000bhy?page=3

    Re: 203410665: listed as '2049 (Eclipsing Binary)' on K2VARCAT, but also as Aperiodic (AP).. Transit-like events are longer so didn't check for a possible period here.

    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)

    203410665 , 2MASS J16253849-2613540 , 8.688 , 7.947 , 7.517 , 0.741 , 0.43 , ('M8V', 0.082) , ('M7V', 0.098)

    T1

    Posted

  • ajamyajax by ajamyajax

    Per @davidbundy77 and from Martti Holst Kristiansen's C2 list also...

    EPIC 204211116 listed as #T-Tauri dipper here:

    http://talk.planethunters.org/#/subjects/APH0000i4g

    204211116: and probably another small dwarf; listed as an EB with P=2.112 on K2VARCAT. But doesn't look exactly periodic to me, so if not a periodic variable maybe this is a young star with interacting and near-periodic dust and debris?

    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)

    204211116 , 2MASS J16214199-2313432 , 12.232 , 11.375 , 10.956 , 0.857 , 0.419 , ('L1V', '...') , ('M7V', 0.098)

    T1

    Posted

  • ajamyajax by ajamyajax

    Per @davidbundy77, probably another T-Tauri dipper:

    http://talk.planethunters.org/#/subjects/APH0000ldb

    Listed as '2003 (Upper Sco Young Star);2056 (Upper Sco Young Star);2085 (rho Oph/Upper Sco)' on K2VARCAT.

    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)

    205080616 , 2MASS J16082324-1930009 , 10.574 , 9.737 , 9.469 , 0.837 , 0.268 , ('L1V', '...') , ('M3V', 0.4)

    T1

    Posted