Close Binary Systems Before and after Mass Transfer - a Comparison of Observations and Theory
Abstract
From a search through the literature 174 close binaries with known absolute dimensions have been sampled. Distinction is made between systems before and after mass exchange. Mass, period and mass ratio distributions and relations of the group of ‘unevolved’ binaries (i.e., prior to mass exchange) are transformed into corresponding distributions and relations of evolved binaries. The transformations are based upon theM 1f=g(M 1f) relation derived from an extended set of published theoretical computations of the evolution of close binaries. From this relation the following characteristics of the system after mass exchange are computed:M 1f,M 2f (andq f),P f. Five different modes of mass transfer were applied for the computation of the values ofP f andM 2f. The variation of the period was calculated using the formalism given by Vanbeverenet al. (1979). The results are compared to the observations of binary systems after mass exchange, and are discussed together with an analysis of the effect of several selection effects present in the distributions. The main conclusion is that, during mass exchange in close binaries, more than 50% of the mass is lost to the system in the process of transfer, removing a large amount of angular momentum.
- Publication:
-
Astrophysics and Space Science
- Pub Date:
- April 1980
- DOI:
- 10.1007/BF00639709
- Bibcode:
- 1980Ap&SS..68..433D
- Keywords:
-
- Binary Stars;
- Mass Transfer;
- Stellar Evolution;
- Stellar Mass;
- Angular Momentum;
- Mass Distribution;
- Mass Ratios;
- Spectrum Analysis;
- Stellar Luminosity;
- Astrophysics