Abstract

Two exoplanet candidates that have recently been discovered with the Kepler mission, KIC 12557548b and KOI-2700b, exhibit transit signals whose shapes suggest that they are accompanied by comet-like dust tails. Since the dust grains in the tails likely originate in the evaporating surfaces of the planets, these objects offer a unique chance to probe the interior of small exoplanets. The precise morphology of the transit signals can be used to put constraints on the composition of the grains in the dust tails, since the evolution of the grains is dictated by material-dependent optical and thermodynamical properties. We self-consistently model the dynamical and size evolution of dust grains released from the planet, by numerically solving the equations of motion and sublimation. We use a radiative transfer code to compute synthetic light curves from the resulting steady-state dust distributions, and compare these with the phase-folded light curves of the two candidates discovered so far.

Presentation

Poster