Mass of Cygnus X-1.
Abstract
Summary. A lower mass limit for Cyg X-l is obtained as a function of distance under the assumption that HDE 226868 is not larger than its Roche lobe and noticing that there are no X-ray eclipses, but with no reference to the mass-luminosity relation. At a distance of 2.5 kpc the minimum mass of Cyg X-1 is 9.5 M0. If HDE 226868 is not allowed to be underluminous for its mass then the distance to the system cannot be much larger than 2 kpc. Key words: binaries black holes X-ray sources
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1974
- Bibcode:
- 1974A&A....34..161P