Back to Volume
Paper: NLTE Calculations of a Na D Doublet in the Atmosphere of the Transiting Planet HD209458b
Volume: 294, Scientific Frontiers in Research on Extrasolar Planets
Page: 467
Authors: Barman, T. S.; Hauschildt, P. H.; Schweitzer, A.; Stancil, P. C.; Baron, E.; Allard, F.
Abstract: The observation of sodium absorption in the atmosphere of HD209458b, currently the only EGP known to transit its parent star, is the first direct evidence 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.
Back to Volume