Publication Date:
2008-11-14
Description:
Using numerical simulation, Holmstrom et al. proposed a plausible alternative explanation of the observed Lyman-alpha absorption that was seen during the transit of HD 209458b (ref. 2). They conclude that radiation pressure alone cannot explain the observations and that a peculiar stellar wind is needed. Here we show that radiation pressure alone can in fact produce the observed high-velocity hydrogen atoms. We also emphasize that even if the stellar wind is responsible for the observed hydrogen, to have a sufficient number of atoms for charge exchange with stellar wind, the energetic neutral atom (ENA) model also needs a significant escape from the planet atmosphere of similar amplitude as quoted in ref. 2.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lecavelier des Etangs, A -- Vidal-Madjar, A -- Desert, J-M -- England -- Nature. 2008 Nov 13;456(7219):E1; discussion E1-2. doi: 10.1038/nature07402.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉CNRS, UMR 7095, Institut d'Astrophysique de Paris, 98bis boulevard Arago, F-75014 Paris, France. lecaveli@iap.fr〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19005500" target="_blank"〉PubMed〈/a〉
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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