A Survey for Very Short-Period Planets in the Kepler Data

Abstract

We conducted a search for very short-period transiting objects in the publicly available Kepler dataset. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than twelve hours. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates' radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates' short periods mean they may induce stellar radial velocity signals (a few m/s) detectable by currently operating facilities. The origins of such short-period planets are unclear, but we discuss the possibility that they may be the remnants of disrupted hot Jupiters. Whatever their origins, if confirmed as planets, these candidates would be among the shortest-period planets ever discovered. Such planets would be particularly amenable to discovery by the planned TESS mission.

Accepted to ApJ and in press; The lead author, Brian Jackson, found a bug in his photocenter analysis code. Correcting this bug reduces from 13 (the original number of candidates reported) to 4 the number of plausible planetary candidates, but the list of false positives is now consistent with false positives reported by the Kepler mission