A pilot investigation to constrain the presence of ring systems around transiting exoplanets

We demonstrate a process by which to evaluate the presence of large, Saturn-like ring systems around transiting extrasolar giant planets. We use extrasolar planet candidate KOI-422.01 as an example around which to establish limits on the presence of ring systems. We find that the spherical-planet (no-rings) fit matches the lightcurve of KOI-422.01 better than a lightcurve with a planet having obliquity angles 90°, 60°, 45°, or 20°. Hence we find no evidence for rings around KOI-422.01, but the methods that we have developed can be used for more comprehensive ring searches in the future. If the Hedman (2015) low-temperature rings hypothesis is correct, then the first positive detection of exorings might require transits of very long period ( ≳ 10 yr) giant planets outside their stars' ice lines.