Collapse and explosion in a rotating star
Abstract
The collapse, bounce, shock wave, and expansion of the envelope of a rotating star have been analyzed in the adiabatic approximation using the particle-in-cell method. The bounce takes place first in the equatorial plane and a shock wave arises there which shortly afterwards crosses the surface of the star. In the envelope, and to a less extent in the remainder of the star, there is a fast and lasting meridional motion whose direction changes. As a consequence of the fast meridional motion in the envelope, mass and angular momentum are transported toward the axis of rotation. If the initial star rotates fast enough this will cause a secondary radial expansion in the polar region and a mass ejection. These motions reduce the strong anisotropy caused originally by the equatorial expansion. Strong whirls may arise along the axis of rotation. In the remainder of the star the meridional motion becomes supersonic. The temperature in the envelope depends to a high degree on the choice of the equation of state. Mass loss is proportional to the energy initially added. The final loss of angular momentum and energy is quite large, both losses being about 25 percent.
- Publication:
-
Astronomische Nachrichten
- Pub Date:
- 1988
- DOI:
- 10.1002/asna.2113090207
- Bibcode:
- 1988AN....309..103R
- Keywords:
-
- Gravitational Collapse;
- Novae;
- Stellar Evolution;
- Stellar Rotation;
- Angular Velocity;
- Polytropic Processes;
- Stellar Mass Ejection;
- Stellar Models;
- Astrophysics