Towards Detection of Exoplanetary Rings Via Transit Photometry: Methodology and a Possible Candidate

Masataka Aizawa, Sho Uehara, Kento Masuda, Hajime Kawahara, Yasushi Suto
(Submitted on 27 Feb 2017)

Detection of a planetary ring of exoplanets remains as one of the most attractive but challenging goals in the field. We present a methodology of a systematic search for exoplanetary rings via transit photometry of long-period planets. The methodology relies on a precise integration scheme we develop to compute a transit light curve of a ringed planet. We apply the methodology to 89 long-period planet candidates from the Kepler data so as to estimate, and/or set upper limits on, the parameters of possible rings. While a majority of our samples do not have a sufficiently good signal-to-noise ratio for meaningful constraints on ring parameters, we find that six systems with a higher signal-to-noise ratio are inconsistent with the presence of a ring larger than 1.5 times the planetary radius assuming a grazing orbit and a tilted ring. Furthermore, we identify five preliminary candidate systems whose light curves exhibit ring-like features. After removing four false positives due to the contamination from nearby stars, we identify KIC 10403228 as a reasonable candidate for a ringed planet. A systematic parameter fit of its light curve with a ringed planet model indicates two possible solutions corresponding to a Saturn-like planet with a tilted ring. There also remain other two possible scenarios accounting for the data; a circumstellar disk and a hierarchical triple. Due to large uncertain factors, we cannot choose one specific model among the three.

Comments:    45 pages, 20 figures, accepted for publication in AJ
Subjects:    Earth and Planetary Astrophysics (astro-ph.EP)
Cite as:    arXiv:1702.08252 [astro-ph.EP] (or arXiv:1702.08252v1 [astro-ph.EP] for this version)
Submission history
From: Masataka Aizawa 
[v1] Mon, 27 Feb 2017 12:15:12 GMT (1300kb)
https://arxiv.org/abs/1702.08252