Colloquia Schedule

Katja Poppenhaeger (CfA)

April 2, 2015, 3:45 p.m. — LGRT 1033
Title: A high-energy view of exoplanets and their host stars

Abstract: Many exoplanets orbit their host stars at close distances, with orbital periods of only a few days. For such systems, the magnetic activity of the planet-hosting star determines the high-energy environment of its exoplanet and is an important factor in understanding the exoplanetary evolution. X-ray and UV observations allow us to determine the high-energy input into the exoplanetary atmosphere, which is the main driver of planetary evaporation. X-ray emission is also directly connected to the stellar rotation; without external input of angular momentum, the star spins down over time due to magnetic braking. However, if there is tidal interaction between a star and its Hot Jupiter, the spin-down of the host star may not follow the usual age/rotation/activity relations. I will discuss recent X-ray and UV observations which provide insights into both the evaporation of close-in exoplanets and a possibly altered age-activity relationship for host stars of such planets.

Pieter van Dokkum (Yale University)

April 9, 2015, 3:45 p.m. — LGRT 1033
Title: A history of the dense cores of massive galaxies

Tracy Webb (McGill University)

April 16, 2015, 3:45 p.m. — LGRT 1033
Title: TBA

Meredith Hughes (TBA)

April 23, 2015, 3:45 p.m. — LGRT 1033
Title: TBA