An extended upper atmosphere around the extrasolar planet HD209458b
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- 1 March 2003
- journal article
- Published by Springer Science and Business Media LLC in Nature
- Vol. 422 (6928), 143-146
- https://doi.org/10.1038/nature01448
Abstract
The planet in the system HD209458 is the first one for which repeated transits across the stellar disk have been observed. Together with radial velocity measurements, this has led to a determination of the planet's radius and mass, confirming it to be a gas giant. But despite numerous searches for an atmospheric signature, only the dense lower atmosphere of HD209458b has been observed, through the detection of neutral sodium absorption. Here we report the detection of atomic hydrogen absorption in the stellar Lyman alpha line during three transits of HD209458b. An absorption of 15 +/- 4% (1sigma) is observed. Comparison with models shows that this absorption should take place beyond the Roche limit and therefore can be understood in terms of escaping hydrogen atoms.Keywords
This publication has 10 references indexed in Scilit:
- An extrasolar planet that transits the disk of its parent starNature, 2003
- Detection of an Extrasolar Planet AtmosphereThe Astrophysical Journal, 2002
- Search for spectroscopical signatures of transiting HD 209458b's exosphereAstronomy & Astrophysics, 2001
- A Search for Transit Effects in Spectra of 51 Pegasi and HD 209458Publications of the Astronomical Society of the Pacific, 2000
- The Spectroscopic Orbit of the Planetary Companion Transiting HD 209458The Astrophysical Journal, 2000
- Detection of Planetary Transits Across a Sun-like StarThe Astrophysical Journal, 2000
- A Transiting “51 Peg–like” PlanetThe Astrophysical Journal, 2000
- Evolution of the solar Lyman alpha flux during four consecutive yearsSolar Physics, 1975
- The Spatial Distribution of LYMAN-a on the SunThe Astrophysical Journal, 1974
- Evolutionary Processes in Close Binary SystemsAnnual Review of Astronomy and Astrophysics, 1971