Studies of hot B subdwarfs. II. Energy distributions of three bright sdB/sdOB stars in the 950-5500 A range.
Abstract
Voyager ultraviolet spectrometer observations of the subdwarf B or OB stars HD 205805, UV 1758+36 and Feige 66 are presented. All three objects display the H I Layman series in absorption. These observations are combined with low dispersion IUE spectrophotometry and with Stromgren photometry to construct virtually complete energy distributions, which extend over the range 950-5500 angstroms. Effective temperatures based on model atmosphere calculations for high gravity, hygrogen rich stars are determined. Our analyses yield Te 28,200 + or - 1300 K for HD 205805, Te 31, 800 + or - 1100 K for UV 1758+36, and Te 35,700 + or 1500 K for Feige 66. The importance of far ultraviolet observations below Lalpha in reducing the uncertainties associated with the interstellar extinction and the degradation of the IUE sensitivity is emphasized.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1985
- DOI:
- 10.1086/163669
- Bibcode:
- 1985ApJ...298..859W
- Keywords:
-
- B Stars;
- Energy Distribution;
- Lyman Spectra;
- Subdwarf Stars;
- Ultraviolet Spectrometers;
- Iue;
- Spectrophotometry;
- Stellar Atmospheres;
- Stellar Temperature;
- Voyager Project;
- Astrophysics