The origin of hydrogen around HD 209458b
Résumé
Lecavelier des Etangs et al. 1 object to the conclusion by Holmström et al. 2 that radiation pressure alone cannot explain the Lyman- absorption observed3 during transits of HD 209458b. We agree that hydrogen atoms can be accelerated to large velocities by radiation pressure. However, with our model we cannot reproduce the observed spectrum, as shown in the Supplementary Information and Fig. 3 of ref. 2.