The photometric behavior of Be stars.
Abstract
Photometric data are presented for 76 Be stars observed in UBV and in the Balmer lines H-alpha, H-beta, and H-gamma. An ultraviolet excess, derived from the Q value, appears as a common feature for nearly all the stars. From a statistical study of the data, the percentages of variability are: 77 percent in V, 48 percent in B-V, and 68 percent in U-B. The amounts of emission in the alpha and beta indices are computed. It is demonstrated that both emission indices are very well correlated with the spectroscopic emission features, their equivalent widths, and possibly also the ultraviolet excess. The correlation of the standard deviation of the V magnitude with the projected rotational velocity is in agreement with a model in which the Balmer line emission is due to a gaseous ring. The observed beta values corrected for the emission indices become good indicators of the absolute magnitudes, as is confirmed by a sample of Be stars known to be members of clusters and associations. Some properties of the galactic distribution of the Be stars are derived.
- Publication:
-
The Astronomical Journal
- Pub Date:
- November 1979
- DOI:
- 10.1086/112600
- Bibcode:
- 1979AJ.....84.1713F
- Keywords:
-
- B Stars;
- Balmer Series;
- Star Distribution;
- Stellar Spectrophotometry;
- Ubv Spectra;
- Dwarf Stars;
- Early Stars;
- Standard Deviation;
- Stellar Envelopes;
- Variable Stars;
- Astronomy;
- Be Stars:Colors;
- Be Stars:Multicolor Photometry;
- Be Stars:UV Excesses