Equilibrium Structure of Stars Obeying a Generalized Differential Rotation Law
Abstract
In the present paper we have considered the problem of determining the equilibrium structure of differentially rotating stars in which the angular velocity of rotation varies both along the axis of rotation and in directions perpendicular to it. For this purpose, a generalized law of differential rotation of the typeω ^{2} =b _{0}+b _{1} s ^{2}+b _{2} s ^{4}+b _{3} z ^{2}+b _{4} z ^{4}+b _{5} z ^{2} s ^{2} (here ω is a nondimensional measure of the angular velocity of a fluid element distants from the axis of rotation andz from the plane through the centre of the star perpendicular to the axis of rotation, andb's are suitably chosen parameters) has been used. Whereas Kippenhahn and Thomas averaging approach has been used to incorporate the rotational effects in the stellar structure equations, Kopal's results on Roche equipotentials have been used to obtain the explicit form of the stellar structure equations, which incorporate the rotational effects up to second order of smallness in the distortion parameters. The method has been used to compute the equilibrium structure of certain differentially rotating polytropes. Certain differentially rotating polytropes. Certain differentially rotating models of the Sun have also been computed by using this approach.
 Publication:

Astrophysics and Space Science
 Pub Date:
 May 1994
 DOI:
 10.1007/BF00627464
 Bibcode:
 1994Ap&SS.215..111M
 Keywords:

 Angular Velocity;
 Gradients;
 Rotating Matter;
 Spin Dynamics;
 Stellar Models;
 Stellar Rotation;
 Differences;
 Fluid Flow;
 Polytropic Processes;
 Solar Rotation;
 Stellar Structure;
 Astrophysics