KID 201677835 - APHC0110081

by zoo3hans

KID 201677835 seems to have a transit every 20.5 days, BKJD 1984.4, 2004.9, 2025.4, 2046.0.

Posted March 24, 2015 3:05 PM

by Dolorous_Edd

Agree

First of all

https://www.cfa.harvard.edu/~avanderb/k2c1/ep201677835.html

SkyView DSS 2 Red 1'x1'

enter image description here

SDSS J114429.64+031620.7

Link to SDSS

Crudely detrended LC

Edit* Updated it, now it looks less atrocious

Download

2MASS

2MASS catalog

Posted March 24, 2015 5:25 PM

by ajamyajax

201677835: also agree, four repeating transits here that could be a high-impact planet. It isn't easy to rule out a bgeb though with minimal data. The depths seem to vary a bit also, but that might be due to blending. Will look at that more later. I did notice the object's period is close to the flux maxima cycle, so maybe near a spin-orbit alignment can help confirm these objects are related(?) Also in the K2 EB catalog as 'aperiodic (or period too long to be identified).'

s1=1984.475 p1=20.51 d1=0.185 (4.44 hours or less)

Posted March 25, 2015 2:19 AM

by Dolorous_Edd

SDSS and 2MASS color - color values

SDSS

g-r = 0.3

u-g = 1.53

r - i = 1.48

Is it G or F star?

2MASS

H-K = 0.065

J-H = 0.527

Posted March 25, 2015 6:26 AM

by ajamyajax

Well, trying another new test... I thought maybe the aperture data could help us identify possible bgeb-type transit offsets or changes in depth. Only four transits here, but perhaps there is some indication of an evolving orbit in this data. So maybe this would support the PC cause here a bit. Also, an odd/even fit here was similar to other sparse data charts and not conclusive in my view.

pbc1
pbp1

Posted March 26, 2015 5:51 PM

by ajamyajax

Ok, what are we to make of this star then? My probability tests show a larger, more metallic star than a cooler M-Dwarf is likely here. And the period/duration match with a theoretical orbit increases the chance this transit is a real object in my view (and more likely a planet).

RA/Dec 176.12355, 3.272425

Semi-Major Axis a (A.U.) = 0.14665

Stellar diameter ratio = 0.891

Stellar mass ratio = 1.0

Period ~= 20.51 days

Duration ~= 4.44 hours

I get this from SDSS: Catalog J H K_s phQual

2MASS 12.43 11.903 11.838 AAA

colors: J-H = 0.527 and H-K = 0.592

(12.43-11.903 = 0.527)

(12.43-11.838 = 0.592)

PB1

Posted May 1, 2015 2:46 PM

by Dolorous_Edd

UKIRT J-band image for EPIC 201677835

1'x1'

enter image description here

Looks rather lonely 😭

Also I have to note that there are some objects visible in K band near EPIC 201677835 ( ~8 arcseconds to the NW direction )

UKIRT K-band

2'x2'

enter image description here

They are SDSS J114429.50+031629.5 and SDSS J114429.13+031625.5 , classified as galaxy by SDSS pipeline

Posted May 1, 2015 3:49 PM

by ajamyajax

Well if it helps, here is a bit more on the stellar or galactic neighborhood:

NEA proximity listing (120 radius arcseconds):

2MASS Objects within search area

2MASS Designation RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] J [mag] V or R [mag] Photometric flags

11442963+0316205 176.123491 3.272376 0.28 12.430 13.60 AAA

11442622+0316131 176.109287 3.270313 51.83 16.196 16.90 BBC

11442522+0314455 176.105116 3.245983 115.98 16.544 16.80 CBU

Their calculated angular distance from 201677835:

201677111 0.81184 minutes or 48.71014 seconds

201677705 0.85989 minutes or 51.59359 seconds

201676869 0.93512 minutes or 56.10705 seconds

201677131 1.11006 minutes or 66.6038 seconds

201678465 1.29445 minutes or 77.66704 seconds

201677312 1.42563 minutes or 85.53798 seconds

201678752 1.4977 minutes or 89.86222 seconds

201679281 1.63519 minutes or 98.11115 seconds

SV1

Posted May 1, 2015 6:20 PM