The extrasolar planet
HD 209458 b


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News: Detection of oxygen and carbon in the hydrodynamically escaping atmosphere of the extrasolar planet HD209458b (2 February 2004)


2 February 2004: The first detection of oxygen and carbon in the atmosphere of an extrasolar planet has been made. This observation has been obtained with the Hubble Space Telescope. This discovery follow a previous one, one year ago, with the detection of an extended atmosphere of hydrogen which is evaporating. The atoms of oxygen and carbon are swept up from the lower atmosphere with the flow of the escaping atmospheric atomic hydrogen, like dust in a supersonic whirlwind. This observation allow to explain why hot Jupiters have orbits that are as brief as 3 days, but not shorter: perhaps the evaporation of the atmosphere plays a role in setting an inner boundary for orbits of hot Jupiters.

Read the press release

ESA site (Press release, animations, etc...) (2 February 2004).

The paper: Detection of oxygen and carbon in the hydrodynamically escaping atmosphere of the extrasolar planet HD209458b, A. Vidal-Madjar J.-M. Désert, A. Lecavelier des Étangs G. Hébrard, G. Ballester, D. Ehrenreich, R. Ferlet, J. C. McConnell, M. Mayor, & C. D. Parkinson, Astrophysical Journal Letters, No. 604, p. L69-L72 (format ps et pdf; astro-ph/0401457).

To read in press...




The evaporating extended hydrogen atmosphere around the extra-solar planet HD209458b (March,13 2003)


Proceedings of the XIXth IAP Colloquium "Extrasolar Planets, Today And Tomorrow" (Paris, June 30 - July 4, 2003) :
  • Vidal-Madjar & Lecavelier des Etangs : "Osiris"(HD209458b), an evaporating planet (astro-ph/0312382).
  • Désert, Vidal-Madjar, Lecavelier des Etangs, Hébrard, Ballester, Ferlet, & Mayor : The data analysis of HD209458 Ly-alpha transit occultation (astro-ph/0312383).
  • Hébrard, Lecavelier des Etangs, Vidal-Madjar, Désert, & Ferlet : Evaporation rate of hot Jupiters and formation of Chthonian planets (astro-ph/0312384).
Press release: An evaporating extra-solar planet. (2003 March 13th)
Article in Nature: An extended upper atmosphere around the extra-solar planet HD209458b, A. Vidal-Madjar A. Lecavelier des Étangs J.-M. Désert, G. Ballester, R. Ferlet, G. Hébrard, & M. Mayor, Nature, Vol. 422, p. 143-146, 13 Mars 2003 ).
ESA site (Press release, animations, etc...)

STScI-NASA site (Press release, animations, etc...)

Artist views of the evaporating extra-solar planet HD209458b
3-D Artist movie (author: Jérémie Vidal-Madjar 3D Infographiste, paris).
Download movie Avi (5 Mo).
A view of the evaporating planet transit.
Download MPEG (13 Mo), Gif (9 Mo), Gif (1 Mo), AVI (3 Mo)
A computer simulation of the evaporating extra-solar planet HD209458b.
Download MPEG (13 Mo), Gif (6 Mo), Gif (1 Mo), AVI (3 Mo)
The Lyman alpha line of the star HD209458, as observed with the Hubble Space Telescope.
The Lyman alpha flux of the star HD209458 as a function of time.
Information related to HD209458 and its planet.
A finding chart of HD209458 in the Pegasus constellation
Some related publications.
Links on this subject.
In press.

Contacts:

desert@iap.fr, hebrard@iap.fr, lecaveli@iap.fr

February, 2nd 2004