Planet erosion by coronal radiation

Sanz-Forcada, J.; Ribas, I.; Micela, G.; Pollock, A.; García-Alvarez, D.; Solano, E.; Eiroa, C.
Bibliographical reference

Highlights of Spanish Astrophysics VI, Proceedings of the IX Scientific Meeting of the Spanish Astronomical Society (SEA), held in Madrid, September 13 - 17, 2010, Eds.: M. R. Zapatero Osorio, J. Gorgas, J. Maíz Apellániz, J. R. Pardo, and A. Gil de Paz., p. 607-612

Advertised on:
11
2011
Number of authors
7
IAC number of authors
1
Citations
0
Refereed citations
0
Description
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 (M_p sin i > 1.5 Mjup) may survive only if exposed to low accumulated coronal radiation. The planet HD~209458~b might have lost more than 1 Mjup already, and other cases, like tau Boo b, could be losing mass at a rate of 3.4 Msol/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.