On the sensitivity of extrasolar mass?loss rate ranges: HD 209458b a case study

VILLARREAL DÀNGELO, C. , SCHNEITER, M., COSTA, A., VELÀZQUEZ, P., RAGA. A., ESQUIVEL, A.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2014 vol. 438 p. 1654 - 1662

0035-8711

We present a 3D hydrodynamic study of the effect that different stellar wind conditions and planetary wind structures have on the calculated Lyα absorptions produced by a cometary tail during transit. We concentrate, as a case study, on the known HD 209458b case. By comparing the numerically obtained Lyα absorption with the observations, we find that the planetary mass loss rate does not change dramatically for large changes in stellar ̇ p range found wind speeds ∼[250 − 800] km s−1 and temperature ∼ [3 − 7] ×106 K. The M is ∼ [3 − 5] × 1010 g s−1 , depending upon the efficiency of the stellar wind to transport heat, (polytropic index Γ ∼ [1.01 − 1.13]), leading to different stellar wind speeds. Several models with anisotropic evaporation profiles for the planetary escaping atmosphere were carried out, showing that both, the escape through polar regions, resembling the emission associated with reconnection processes, and through the night side, produced by a strong stellar wind that compresses the planetary atmosphere and inhibits its escape from the day h