Spectroscopic studies of Wolf-rayet stars with absorption lines. VII.HD 156327 and HD 192641 and the question of WR duplicity.
Abstract
The two WC7 stars HD 156327 and HD 192641 contain absorption lines of the Balmer series. A detailed radial velocity study limits any orbital motion of the WC stars to K less than approximately 20 km/sec for P less than approximately 2 years. The absorption lines may be intrinsic or due to a distant companion, but these limits essentially preclude the possibility that either of these is a close WR binary. Of the 12 well-studied northern hemisphere WR stars with absorption lines, only seven are binaries. The other five appear to be 'single', in the sense that they do not have massive, close companions. Thus the presence of absorption lines in the spectrum of a WR star is not a sufficient condition for assuming duplicity. The binary frequency argument given by Vanbeveren and Conti is rediscussed, with the conclusion that the total percentage of WR binaries (including those with collapsed companions) may be less than approximately 50%, the same as for O stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1981
- DOI:
- 10.1086/158907
- Bibcode:
- 1981ApJ...246..145M
- Keywords:
-
- Absorption Spectra;
- Binary Stars;
- Hot Stars;
- Radial Velocity;
- Spectrum Analysis;
- Stellar Spectra;
- Wolf-Rayet Stars;
- Balmer Series;
- Emission Spectra;
- Stellar Evolution;
- Astronomy