Thursday, 20 June 2019

[20 December 2013] Found: Planets Skimming a Star’s Surface

A new planet-hunting survey has revealed planetary candidates with orbitalperiods as short as four hours and so close to their host stars that they arenearly skimming the stellar surface. If confirmed, these candidates would beamong the closest planets to their stars discovered so far. DTM Post DoctoralFellow, Brian Jackson, presented his team’s findings, which are based on datafrom NASA’s Kepler mission.  Most gas giant exoplanets with orbital periods less than or equal to a few days are unstable. This is due to decay in their orbits caused by the effects of their star’s proximity. For rocky or icy planets, this disruption could bring them close enough to the star that the force of their own gravity can no longer hold them together in the face of the star’s gravity. Motivated by these considerations, Jackson’s team conducted a search for very short-period transiting objects in the publicly available Kepler dataset. Their preliminary survey revealed four planetary candidates, all with periods less than 12 hours. The origins of such short-period planets are unclear, but they may be the remnants of disrupted hot Jupiters.  This work appeared in the 20 December 2013 issue of The Astrophysical Journal.