Instability in the red star of semi-detached binary systems
Abstract
The solution of the linear adiabatic wave equation has been found for a range of evolutionary models in both single-star and binary (line-of-centres) gravitational potentials, with Eulerian and Lagrangian surface pressure boundary conditions. The eigenvalues determining the stability of the envelope from different boundary conditions converge onto the same dynamically unstable value as the stellar surface approaches the L1 point. The properties of this instability are shown to be well correlated with the position and existence of the hydrogen/helium I ionization zone. Off-line-of-centres calculations show that the instability patch about the L1 point is approximately 15 scale-heights in radius for a typical 1 M_sun; main-sequence star.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 1985
- DOI:
- 10.1093/mnras/212.3.623
- Bibcode:
- 1985MNRAS.212..623E
- Keywords:
-
- Binary Stars;
- Companion Stars;
- Stellar Evolution;
- Stellar Models;
- Adiabatic Conditions;
- Eigenvalues;
- Helium;
- Hydrogen;
- Linear Equations;
- Roche Limit;
- Astrophysics