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

VILLARREAL D`ANGELO; SCHNEITER E. MATIAS; COSTA, ANDREA; PABLO F. VELÁZQUEZ; RAGA, A. C.; ESQUIVEL, A

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 vol. 438 p. 1654 - 1654

0035-8711

e 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. Initially we assume a broad range of possible planetary mass loss rate values: Mp =[1 − 7] ×10^10g s^−1. Then, by comparing the observational Lyα absorption with the numerically derived ones, we could constrain the ˙Mp values within the given range. We find that the planetary mass loss rate does not change dramatically for large changes in stellar wind speeds ∼[250 − 800] km s^−1 and temperature ∼ [3 − 7] ×10^6 K while keeping fixed the stellar mass loss rate ( ˙M = 9.0 × 10^−14 M_sun yr^−1). The Mp range found is ∼ [3 − 5] × 10^10g s^−1, depending upon the efficiency of the stellar wind to transport heat, (polytropic index Γ