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Paper: Planets and X-rays: a Radiation Diet
Volume: 448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun
Page: 1247
Authors: Sanz-Forcada, J.; Ribas, I.; Micela, G.; Pollock, A.; Garcìa-Àlvarez, D.; Solano, E.; Eiroa, C.
Abstract: According to theory, high energy emission from the coronae of cool stars can severely erode the atmosphere of orbiting planets. To test the long term effects of the erosion we study a large sample of planet-hosting stars observed in X-rays. The results reveal that massive planets (Mpsin i >1.5 MJ) may survive only if exposed to low accumulated coronal radiation. The planet HD 209458 b might have lost more than 1 MJ already, and other cases, like τ Boo b, could be losing mass at a rate of 3.4 M/Gyr. The strongest erosive effects would take place during the first stages of the stellar life, when the faster rotation generates more energetic coronal radiation. The planets with higher density seem to resist better the radiation effects, as foreseen by models. Current models need to be improved to explain the observed distribution of planetary masses with the coronal radiation received.
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