Poster Abstracts

Name/Affiliation:  Katja Poppenhaeger (Harvard-Smithsonian Center for Astrophysics)

Title:  A tale of two exoplanets: X-ray studies of the Hot Jupiters HD 189733 b and CoRoT-2 b

Planets in close orbits around their host stars are subject to strong irradiation. Especially high-energy irradiation, originating from the stellar corona and chromosphere, is responsible for the evaporation of exoplanetary atmospheres. Observations at short wavelenghts are therefore a prime tool to study the planetary mass loss. We have conducted multiple X-ray observations of transiting exoplanets in short orbits to determine the extent and heating of their outer planetary atmospheres. In the case of HD 189733 b, we find a surprisingly deep transit profile in X-rays, indicating an atmosphere extending out to 1.75 optical planetary radii. We will also report on observations of the Hot Jupiter CoRoT-2 b from our Large Program with XMM-Newton, which was conducted recently.