A tale of two exoplanets: the inflated atmospheres of the Hot Jupiters HD 189733 b and CoRoT-2 b

K. Poppenhaeger, S.J. Wolk, J.H.M.M. Schmitt

(Submitted on 14 Aug 2014)

Planets in close orbits around their host stars are subject to strong irradiation. High-energy irradiation, originating from the stellar corona and chromosphere, is mainly responsible for the evaporation of exoplanetary atmospheres. 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. The X-ray opacity of those high-altitude layers points towards large densities or high metallicity. We preliminarily report on observations of the Hot Jupiter CoRoT-2 b from our Large Program with XMM-Newton, which was conducted recently. In addition, we present results on how exoplanets may alter the evolution of stellar activity through tidal interaction.

Comments:

To appear in the Proceedings of the 18th Cool Stars Workshop (Flagstaff 2014)

Subjects:

Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

Cite as:

arXiv:1408.3385 [astro-ph.SR] (or arXiv:1408.3385v1 [astro-ph.SR] for this version)

Submission history

From: Katja Poppenhaeger 

[v1] Thu, 14 Aug 2014 18:58:30 GMT (428kb,D)

http://arxiv.org/abs/1408.3385

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