Studies of hot B subdwarfs. III. Carbon, nitrogen and silicon abundances in three sdB stars.
Abstract
Optical and high-dispersion IUE observations of three hot B subdwarfs (UV 1758 + 36, Ton S-227, and Feige 65) are presented. These data are analyzed with model atmosphere techniques, and element abundances for C, N, and Si are derived. The abundances are either near (N) or below (C, Si) the solar value; large variations (1) in the extent of underabundances of carbon and silicon among the objects, as well as (2) in the abundances (with respect to the solar values) characterizing each star are observed. A preliminary interpretation of the observed variations in these and other hot subdwarfs in terms of radiative forces disrupting the downward diffusion of heavy elements is presented.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1985
- DOI:
- 10.1086/163716
- Bibcode:
- 1985ApJ...299..496L
- Keywords:
-
- Abundance;
- B Stars;
- Carbon;
- Nitrogen;
- Silicon;
- Stellar Spectra;
- Subdwarf Stars;
- Hot Stars;
- Iue;
- Spectrum Analysis;
- Stellar Atmospheres;
- Stellar Composition;
- Ultraviolet Spectra;
- Visible Spectrum;
- Astrophysics