The far-ultraviolet energy distribution of two globular cluster blue horizontal-branch stars in M 13.
Abstract
The far-UV energy distribution of two blue horizontal-branch (BHB) stars detected in the nucleus of M13 is presented. Their continua can be characterized by a model atmosphere of an effective temperature of 15,000 to 20,000 K and log g = 4.5, and it follows that V is in the range 15.9-16.7 for these stars. Comparison with integrated photometry by OAO 2 and by ANS indicates that, at wavelengths smaller than 1800 A, the integrated light is from BHB stars only, of which M13 contains about 200. For these far-UV wavelengths, the color of the BHB stars is also very similar to the integrated color of the elliptical galaxy M87.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1981
- DOI:
- 10.1086/183437
- Bibcode:
- 1981ApJ...243L..33D
- Keywords:
-
- Far Ultraviolet Radiation;
- Globular Clusters;
- Spectral Energy Distribution;
- Stellar Spectra;
- Ultraviolet Spectra;
- Elliptical Galaxies;
- Iue;
- Star Distribution;
- Stellar Spectrophotometry;
- Stellar Temperature;
- Astronomy