Model atmospheres of very low mass stars and brown dwarfs

France Allard, Peter H. Hauschildt, David R. Alexander, Sumner Starrfield

Research output: Contribution to journalArticle

257 Citations (Scopus)

Abstract

As progressively cooler stellar and substellar objects are discovered, the presence first of molecules and then of condensed particulates greatly complicates the understanding of their physical properties. Accurate model atmospheres that include these processes are the key to establishing their atmospheric parameters. They play a crucial role in determining structural characteristics by setting the surface conditions of model interiors and providing transformations to the various observational planes. They can reveal the spectroscopic properties of brown dwarfs and help establish their detectability. In this paper, we review the current state-of-the-art theory and modeling of the atmospheres of very low mass stars, including the coolest known M dwarfs, M subdwarfs, and brown dwarfs, i.e. Teff ≤ 4,000 K and -4.0 ≤ [M/H] ≤ +0.0. We discuss ongoing efforts to incorporate molecular and grain opacities in cool stellar spectra, as well as the latest progress in (a) deriving the effective temperature scale of M dwarfs, (b) reproducing the lower main sequences of metal-poor subdwarfs in the halo and globular clusters, and (c) results of the models related to the search for brown dwarfs.

Original languageEnglish (US)
Pages (from-to)137-177
Number of pages41
JournalAnnual Review of Astronomy and Astrophysics
Volume35
Issue number1
StatePublished - 1997

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atmospheres
stars
atmosphere
stellar spectra
temperature scales
opacity
globular clusters
coolers
particulates
halos
physical property
physical properties
metal
metals
modeling
molecules
temperature
state of the art
parameter

Keywords

  • Brown dwarfs
  • Low mass stars
  • Stellar atmospheres
  • Stellar fundamental parameters

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Model atmospheres of very low mass stars and brown dwarfs. / Allard, France; Hauschildt, Peter H.; Alexander, David R.; Starrfield, Sumner.

In: Annual Review of Astronomy and Astrophysics, Vol. 35, No. 1, 1997, p. 137-177.

Research output: Contribution to journalArticle

Allard, F, Hauschildt, PH, Alexander, DR & Starrfield, S 1997, 'Model atmospheres of very low mass stars and brown dwarfs', Annual Review of Astronomy and Astrophysics, vol. 35, no. 1, pp. 137-177.
Allard, France ; Hauschildt, Peter H. ; Alexander, David R. ; Starrfield, Sumner. / Model atmospheres of very low mass stars and brown dwarfs. In: Annual Review of Astronomy and Astrophysics. 1997 ; Vol. 35, No. 1. pp. 137-177.
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