Ultraviolet observations of Population II Cepheids.
Abstract
The two Population II Cepheids, ST Pup and W Vir, have nearly the same length of period and B-V colors, yet spectral types are very different, indicating large differences in metal abundances. The authors have determined metal abundances, Teff and the color excess from the observed discontinuities at 1700 Å, at 2600 Å, the ultraviolet to visual colors, and the 2400 Å absorption band. The observations for ST Pup were made shortly after maximum light. For ST Pup the authors found E(B-V) = 0.2, Teff = 6600±100K at 0.5 days after maximum. A metal abundance of [A/H] = -1.7±0.2 was determined. For W Vir a metal abundance of [A/H] ≡ -0.9 is suggested.
- Publication:
-
NASA Conference Publication
- Pub Date:
- December 1984
- Bibcode:
- 1984NASCP2349..348B
- Keywords:
-
- Astronomy;
- Color Excesses:Population II Cepheids;
- Effective Temperatures:Population II Cepheids;
- Metal Abundances:Population II Cepheids;
- Population II Cepheids:Color Excesses;
- Population II Cepheids:Effective Temperatures;
- Population II Cepheids:Metal Abundances;
- Cepheid Variables;
- Energy Distribution;
- Iue;
- Metallic Stars;
- Spectrum Analysis;
- Ultraviolet Spectra;
- Metallic Plasmas;
- Stellar Structure;
- Ultraviolet Astronomy;
- Variable Stars