The evolution of low-mass close binary systems. VI. Population II W Ursae Majoris systems.
Abstract
A grid of parametric models of hypothetical metal-poor W Ursae Majoris-type binaries is evolved to typical globular-cluster ages. Constraints on the initial masses and mass ratios of such binaries are discussed. It is shown that gravitational radiation profoundly affects the distribution of observable parameters of present-day systems, which consequently have very extreme mass ratios (no more than about 0.18), small eclipse depths (no greater than about 0.4), and short periods, less than or approximately equal to 0.33 day. No severe constraints can yet be put on the frequency of such objects in globular clusters.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1979
- DOI:
- 10.1086/156717
- Bibcode:
- 1979ApJ...227..178W
- Keywords:
-
- Eclipsing Binary Stars;
- Globular Clusters;
- Gravitational Effects;
- Mass Ratios;
- Stellar Evolution;
- Angular Momentum;
- Mass Distribution;
- Nuclear Interactions;
- Stellar Mass;
- Stellar Models;
- Astrophysics;
- Close Binaries:Evolution;
- Close Binaries:Globular Clusters;
- Globular Clusters:W UMa Stars;
- Population II Stars:W UMa Stars