Photometric observations and interpretation of the extremely hydrogen-deficient binary upsilon Sagittarii.
Abstract
The results of a detailed photometric investigation of the extremely hydrogen-deficient binary υ Sgr are presented. The nature of the quasi-periodic 20-day variation previously reported can be understood in terms of radial pulsation of the supergiant primary component. From observational and theoretical considerations, the secondary component can best be understood as an early B-type main-sequence star with a mass of ≡11 M_sun;, much higher than previously thought. υ Sgr does not appear to be capable or providing an evolutionary link to the R CrB and extreme helium stars. Drastic orbital shrinkage during a future common-envelope episode could draw the binary components sufficiently close together to result in a Type I supernova.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 1988
- DOI:
- 10.1093/mnras/233.3.621
- Bibcode:
- 1988MNRAS.233..621M
- Keywords:
-
- Astronomical Photometry;
- Binary Stars;
- Main Sequence Stars;
- Stellar Mass;
- Stellar Oscillations;
- Supergiant Stars;
- Companion Stars;
- Light Curve;
- Mass Transfer;
- Sagittarius Constellation;
- Stellar Evolution;
- Stellar Mass Ejection;
- Ubv Spectra;
- Astronomy