Rapidly Rotating Stars. III. Massive MainSequence Stars.
Abstract
The effects of rapid differential rotation on the structure and observable properties of mainsequence stars of 20100 Mo have been studied using the selfconsistentfield method of Ostriker and Mark for the potential theory, while the thermal conditions have been treated in such a way that the energy carried by meridional currents is averaged out. The rotation field is assumed constant on cylinders coaxial with the rotation axis, as is suggested by the stability analysis of Goldreich and Schubert. In order to simplify the analysis, a polytropic P(p)relation is assumed. This latter assumption restricts the appli cability of the investigation to the mass range of the 0 stars, although the qualitative physical results should apply also to rapidly rotating B stars. It has been found that differential rotation (with angular velocity decreasing outward and with equatorial velocities of the observed order) can cause deficiencies of 1 or 2 mag in Mb01 In general, the effects of differential rotation are up to an order of magnitude larger than those of uniform rotation for the same equatorial velocity. Furthermore, differential rotation shifts the position of the star in the HR diagram almost downward along the main sequence, so that a star with rapid differential rotation may be as much as twice as massive as a nonrotating star of the same effective temperature and absolute magnitude
 Publication:

The Astrophysical Journal
 Pub Date:
 November 1968
 DOI:
 10.1086/149785
 Bibcode:
 1968ApJ...154..627M