Non-LTE effects of Na I in the atmosphere of HD 209458b

Travis S Barman, Peter H. Hauschildt, Andreas Schweitzer, Phillip C. Stancil, E. Baron, France Allard

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The recent announcement that sodium absorption has been observed in the atmosphere of HD 209458b, the only extrasolar giant planet (EGP) observed to transit its parent star, is the first direct detection of an EGP atmosphere. We explore the possibility that neutral sodium is not in local thermodynamic equilibrium (LTE) in the outer atmosphere of irradiated EGPs and that the sodium concentration may be underestimated by models that make the LTE assumption. Our results indicate that it may not be necessary to invoke excessive photoionization, low metallicity, or even high-altitude clouds to explain the observations.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume569
Issue number1 II
DOIs
StatePublished - Apr 10 2002
Externally publishedYes

Fingerprint

thermodynamic equilibrium
thermodynamics
local thermodynamic equilibrium
sodium
atmospheres
atmosphere
planets
planet
high altitude
transit
metallicity
photoionization
stars
effect

Keywords

  • Planetary systems
  • Radiative transfer

ASJC Scopus subject areas

  • Space and Planetary Science
  • Nuclear and High Energy Physics

Cite this

Barman, T. S., Hauschildt, P. H., Schweitzer, A., Stancil, P. C., Baron, E., & Allard, F. (2002). Non-LTE effects of Na I in the atmosphere of HD 209458b. Astrophysical Journal, 569(1 II). https://doi.org/10.1086/340579

Non-LTE effects of Na I in the atmosphere of HD 209458b. / Barman, Travis S; Hauschildt, Peter H.; Schweitzer, Andreas; Stancil, Phillip C.; Baron, E.; Allard, France.

In: Astrophysical Journal, Vol. 569, No. 1 II, 10.04.2002.

Research output: Contribution to journalArticle

Barman, TS, Hauschildt, PH, Schweitzer, A, Stancil, PC, Baron, E & Allard, F 2002, 'Non-LTE effects of Na I in the atmosphere of HD 209458b', Astrophysical Journal, vol. 569, no. 1 II. https://doi.org/10.1086/340579
Barman TS, Hauschildt PH, Schweitzer A, Stancil PC, Baron E, Allard F. Non-LTE effects of Na I in the atmosphere of HD 209458b. Astrophysical Journal. 2002 Apr 10;569(1 II). https://doi.org/10.1086/340579
Barman, Travis S ; Hauschildt, Peter H. ; Schweitzer, Andreas ; Stancil, Phillip C. ; Baron, E. ; Allard, France. / Non-LTE effects of Na I in the atmosphere of HD 209458b. In: Astrophysical Journal. 2002 ; Vol. 569, No. 1 II.
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