Centaurus X-3.
Abstract
Spectroscopic observations of Krzeminski's star at dispersions 25-60 A/mm are described. The primary is an evolved star of type O6-O8(f) with peculiarities, some of which are attributable to X-ray heating. Broad emission lines at 4640A (N III), 4686 A(He II) and H-alpha show self-absorption and do not originate entirely from the region near the X-ray star. The primary is not highly luminous (bolometric magnitude about -9) and does not show signs of an abnormally strong stellar wind. The X-ray source was 'on' at the time of optical observations. Orbital parameters are presented for the primary, which yield masses of 17 + or - 2 and 1.0 + or - 3 solar masses for the stars. The optical star is undermassive for its luminosity, as are other OB-star X-ray primaries. The rotation is probably synchronized with the orbital motion. The distance to Cen X-3 is estimated to be 10 + or - 1 kpc. Basic data for 12 early-type X-ray primaries are discussed briefly
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1979
- DOI:
- 10.1086/157042
- Bibcode:
- 1979ApJ...229.1079H
- Keywords:
-
- Astronomical Spectroscopy;
- Binary Stars;
- Early Stars;
- X Ray Sources;
- Emission Spectra;
- O Stars;
- Orbits;
- Stellar Luminosity;
- Astrophysics;
- Early-Type Stars:X-Ray Binaries;
- Spectra:X-Ray Binaries