Rapidly Rotating Stars.VI. Pre-Main - Evolution of Massive Stars
Abstract
The evolution of differentially rotating stars in the range 3-12 Al0 during the radiative portion of the pre-main-sequence contraction is calculated, under the assumptions of axial symmetry, a polytropic (P, p) -relation, and conservation of angular momentum. The results show that (1) an increase in the total angular momentum for a given mass has a substantial effect on the evolutionary track, (2) contracting stars which reach the vicinity of the main sequence with calculated surface velocities in the observed range exhibit a considerably different mass-luminosity relation from that of nonrotating stars, (3) models with total angular momenta above a certain critical value may form binary systems by fission before nuclear reactions can stop the contraction, and (4) in these detailed calculations the phenomena known as "equatorial mass loss" or "rotational mass ejection" never occur. Calculated models are compared with observations of rotational velocities in young stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1970
- DOI:
- 10.1086/150610
- Bibcode:
- 1970ApJ...161.1101B