He I lines in B stars: Comparison of non-local thermodynamic equilibrium models with observations

Journal Article · Mon Nov 15 04:00:00 EST 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160459· OSTI ID:5705411

Heasley, J N; Wolff, S C; Timothy, J G

Profiles of He I lambdalambda4026, 4387, 4471, 4713, 5876, and 6678 have been obtained in 17 stars of spectral type B0--B5. Parameters of the non-local thermodynamic equilibrium models (Auer and Mihalas 1973) appropriate to each star are determined from the Stromgren c/sub 0/ index and fits to H..cap alpha.. line profiles. We find that these parameters yield generally good fits to the observed He I line profiles, with the best fits being found for the blue He I lines where departures from local thermodynamic equilibrium are relatively small. For the two red lines (lambdalambda5876 and 6678) we find that, in the early B stars and in stars with log g<3.5, both lines are systematically stronger than predicted by the non-local thermodynamic equilibrium models.

• Research Organization: Institute for Astronomy, University of Hawaii
• OSTI ID: 5705411
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 262:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics &amp; Cosmology-- Stars &amp; Quasi-Stellar
Radio &amp; X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BALMER LINES
ELEMENTS
EQUILIBRIUM
FLUIDS
GASES
HELIUM
MAIN SEQUENCE STARS
MATHEMATICAL MODELS
NONMETALS
PARTICLE MODELS
RARE GASES
SPECTRA
STAR MODELS
STARS
STATISTICAL MODELS
STELLAR ATMOSPHERES
THERMODYNAMIC MODEL
VISIBLE SPECTRA