|
|
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. |
|
|
|
|