White dwarfs with carbon bands.
Abstract
Lick Observatory spectrophotometry is presented for three recognized 4670-A stars (G47-18, G99-37, and G257-38) and the DC star L1363-3. New C I features are reported for G47-18; G257-38 has no C I but definite C2; weak bands are also noted in L1363-3, which is a Wolf 219 group member. The magnetic CH star G99-37 is examined in greater detail. Model-atmosphere calculations show that it must have a helium-dominated atmosphere, since stringent upper limits on H-alpha and H-beta central Zeeman components are found. The CH 'G' band profile is compared with the theoretical calculations of Angel and Landstreet (1974). Other upper limits for atomic lines are discussed.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- February 1977
- DOI:
- 10.1086/130077
- Bibcode:
- 1977PASP...89...78L
- Keywords:
-
- Atmospheric Models;
- Carbon Stars;
- Magnetic Stars;
- Stellar Models;
- Stellar Spectrophotometry;
- White Dwarf Stars;
- H Alpha Line;
- H Beta Line;
- Helium;
- Hydrocarbons;
- Zeeman Effect;
- Astrophysics;
- Atmospheres:White Dwarfs;
- Magnetic Stars:White Dwarfs;
- Molecules:White Dwarfs