Abstract:  Planetary properties evolve in time; there is detailed evidence for dramatic evolution of the Solar System planets, but evidence from exoplanets is only emerging now. While most individual planets evolve slowly, exoplanet populations offer an opportunity to study the evolution of e.g. planetary orbits, radii, and atmospheres. In this talk, I will discuss promising avenues for observationally constraining the evolution of close-in, low-mass exoplanets, which are the most common outcome of the planet formation process that we know of. In particular, I will present evidence that the radius valley, which separates rocky super-Earths from gaseous sub-Neptunes, fills in over gigayear timescales. These observations are due to a lack of large super-Earths at ages <2-3 Gyr, indicating that the largest and most massive cores may lose their atmospheres at late times. I will also discuss how case studies of young transiting planets are helping us understand the initial conditions of close-in planets and atmospheric loss processes in finer detail. 

Host:  Dan Stevens

Please click the link to join the webinar: https://psu.zoom.us/j/96060188956