Orbital changes of the gaseous ring around Be stars. II. Apsidal motion and slow drift of the orbital elements.
Abstract
It is shown that the observed data about the apsidal motion of gaseous rings around some Be stars, like Beta(1) Mon and Pi Aqr, cannot be explained solely by the influence of the equatorial bulge. This fact has prompted the development of a theory of apsidal motion and slow drift of orbital elements that is based on the mixing of slowly escaping gases from the central star with gases in the emission ring around it. Thus, the basic physical idea in this paper follows closely what has been advanced in the first paper of this series but the mathematical treatment has been broadened in order to deal with the actual orbits, instead of osculating orbits, of particles in the ring. In accordance with this theory, it is believed that in cases where no mixing of gases takes place, the apsidal motion is controlled solely by the equatorial bulge. But in cases where mixing takes place, the apsidal motion depends upon the manner of gas mixing as well.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1978
- DOI:
- 10.1086/155859
- Bibcode:
- 1978ApJ...219..956H
- Keywords:
-
- B Stars;
- Gas Dynamics;
- Orbital Elements;
- Stellar Envelopes;
- Apsides;
- Eccentric Orbits;
- Equations Of Motion;
- Ring Structures;
- Stellar Evolution;
- Astronomy;
- Be Stars:Circumstellar Shells