An extended upper atmosphere around the extrasolar planet HD209458b

A. Vidal-Madjar; A. Lecaveller des Etangs; J. M. Désert; G. E. Ballester; R. Ferlet; G. Hébrard; M. Mayor

doi:10.1038/nature01448

An extended upper atmosphere around the extrasolar planet HD209458b

A. Vidal-Madjar, A. Lecaveller des Etangs, J. M. Désert, G. E. Ballester, R. Ferlet, G. Hébrard, M. Mayor

Lunar and Planetary Lab

Research output: Contribution to journal › Article › peer-review

895 Scopus citations

Abstract

The planet in the system HD209458 is the first one for which repeated transits across the stellar disk have been observed^1,2. Together with radial velocity measurements³, 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 signaturen^4-6, only the dense lower atmosphere of HD209458b has been observed, through the detection of neutral sodium absorption⁷. Here we report the detection of atomic hydrogen absorption in the stellar Lyman α line during three transits of HD209458b. An absorption of 15 ± 4% (1σ) 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.

Original language	English (US)
Pages (from-to)	143-146
Number of pages	4
Journal	Nature
Volume	422
Issue number	6928
DOIs	https://doi.org/10.1038/nature01448
State	Published - Mar 13 2003

ASJC Scopus subject areas

General

Access to Document

10.1038/nature01448

Cite this

@article{877b1ae52f7f47d4b2bc5b2ce6234039,

title = "An extended upper atmosphere around the extrasolar planet HD209458b",

abstract = "The planet in the system HD209458 is the first one for which repeated transits across the stellar disk have been observed1,2. Together with radial velocity measurements3, 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 signaturen4-6, only the dense lower atmosphere of HD209458b has been observed, through the detection of neutral sodium absorption7. Here we report the detection of atomic hydrogen absorption in the stellar Lyman α line during three transits of HD209458b. An absorption of 15 ± 4% (1σ) 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.",

author = "A. Vidal-Madjar and {Lecaveller des Etangs}, A. and D{\'e}sert, {J. M.} and Ballester, {G. E.} and R. Ferlet and G. H{\'e}brard and M. Mayor",

note = "Funding Information: Acknowledgements T.H.H. thanks NRAO and NAIC for partial sabbatical leave support at the Green Bank and Arecibo Observatories. J.S.K. thanks NRAO for pre-doctoral support. We thank B. Driggers of TMS and LeCroy for the loan of a LeCroy LT584L oscilloscope, J. Ford at NRAO Green Bank for square-law detectors, NRAO Socorro for computer support and technical assistance, and the NSF for a research grant. The Arecibo Observatory is operated by Cornell University under a cooperative agreement with the National Science Foundation.",

year = "2003",

month = mar,

day = "13",

doi = "10.1038/nature01448",

language = "English (US)",

volume = "422",

pages = "143--146",

journal = "Nature",

issn = "0028-0836",

publisher = "Nature Research",

number = "6928",

}

TY - JOUR

T1 - An extended upper atmosphere around the extrasolar planet HD209458b

AU - Vidal-Madjar, A.

AU - Lecaveller des Etangs, A.

AU - Désert, J. M.

AU - Ballester, G. E.

AU - Ferlet, R.

AU - Hébrard, G.

AU - Mayor, M.

N1 - Funding Information: Acknowledgements T.H.H. thanks NRAO and NAIC for partial sabbatical leave support at the Green Bank and Arecibo Observatories. J.S.K. thanks NRAO for pre-doctoral support. We thank B. Driggers of TMS and LeCroy for the loan of a LeCroy LT584L oscilloscope, J. Ford at NRAO Green Bank for square-law detectors, NRAO Socorro for computer support and technical assistance, and the NSF for a research grant. The Arecibo Observatory is operated by Cornell University under a cooperative agreement with the National Science Foundation.

PY - 2003/3/13

Y1 - 2003/3/13

N2 - The planet in the system HD209458 is the first one for which repeated transits across the stellar disk have been observed1,2. Together with radial velocity measurements3, 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 signaturen4-6, only the dense lower atmosphere of HD209458b has been observed, through the detection of neutral sodium absorption7. Here we report the detection of atomic hydrogen absorption in the stellar Lyman α line during three transits of HD209458b. An absorption of 15 ± 4% (1σ) 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.

AB - The planet in the system HD209458 is the first one for which repeated transits across the stellar disk have been observed1,2. Together with radial velocity measurements3, 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 signaturen4-6, only the dense lower atmosphere of HD209458b has been observed, through the detection of neutral sodium absorption7. Here we report the detection of atomic hydrogen absorption in the stellar Lyman α line during three transits of HD209458b. An absorption of 15 ± 4% (1σ) 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.

UR - http://www.scopus.com/inward/record.url?scp=0037435005&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037435005&partnerID=8YFLogxK

U2 - 10.1038/nature01448

DO - 10.1038/nature01448

M3 - Article

C2 - 12634780

AN - SCOPUS:0037435005

SN - 0028-0836

VL - 422

SP - 143

EP - 146

JO - Nature

JF - Nature

IS - 6928

ER -

An extended upper atmosphere around the extrasolar planet HD209458b

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this