Atmospheres of T Tauri stars: The photosphere and low chromosphere

Journal Article · Sat Dec 15 04:00:00 EST 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157578· OSTI ID:5684525

Cram, L E

A model for the photospheric and low chromospheric regions of the atmosphere of an advanced T Tauri star has been constructed, by superposing an a hoc temperature rise on a theoretical model photosphere. This model has been used to synthesize several spectral features, including the continuum from 300 A to 300 ..mu..m; the Fe I and Fe II spectrum in the interval 4475--4500 A; the hydrogen lines H..cap alpha.., ..beta.., ..gamma..; Ca I lambda4227; Ca II H, K and the IR triplet; and Na D. A comparision between these predictions and observations supports the conclusion that T Tauri stars possess a chromosphere that begins relatively deep in the atmosphere, with the beginning depth of the chromosphere principally determining the degree of advancement of the T Tauri spectrum. There are a number of spectral features that cannot be explained by this model, including the near-IR excess, the large H..cap alpha..:H..beta.. decrement, and the asymmetry of emission lines.

• Research Organization: Sacramento Peak Observatory, Sunspot, New Mexico
• OSTI ID: 5684525
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 234:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
ALKALINE EARTH METALS
ATMOSPHERES
BALMER LINES
CALCIUM
CHEMICAL COMPOSITION
CRYOGENIC FLUIDS
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION SPECTRA
ENERGY SPECTRA
ERUPTIVE VARIABLE STARS
FLUIDS
HYDROGEN
INFRARED RADIATION
IRON
MATHEMATICAL MODELS
METALS
NONMETALS
RADIATIONS
SODIUM
SPECTRA
STAR MODELS
STARS
STELLAR ATMOSPHERES
T TAURI STARS
TRANSITION ELEMENTS
VARIABLE STARS