10/26 ITC Colloquium - Hilke Schlichting (UCLA)


Thursday, October 26, 2017, 11:00am to 12:00pm



"Formation of super-Earths"

Abstract: Recent observations by the Kepler space telescope have led to the discovery of more than 4000 exoplanet candidates consisting of many systems with Earth- to Neptune-sized objects that reside well inside the orbit of Mercury, around their respective host stars. How and where these close-in planets formed is one of the major unanswered questions in planet formation. I will present new results that self-consistently treat the nebular gas accretion onto rocky cores and the subsequent evolution of gas envelopes due to cooling and photo-evaporation following the dispersal of the protoplanetary disk. I will demonstrate that planets shed their outer layers (dozens of percent in mass) following the disk's dispersal (even without photo-evaporation), and that their atmospheres shrink in a few Myr to a thickness comparable to the radius of the underlying rocky core. I will conclude with comparing our new results with observations and discussing the implications for the origin and formation of terrestrial planets in our solar system and for close in exoplanets.

See also: Colloquium, 2017-18