On the oscillations and the stability of rotating gaseous masses. II. The homogeneous, compressible model

Abstract

The pulsation frequencies of rotating, gaseous masses of uniform density, i.e., of the Maclaurin spheroids, are found as functions of the angular momentum M and the ratio of the specific heats γ. Numerical calculations for the pulsation frequencies and normal modes are given for γ = 1.3, 4/3, 1.4, 1.5, 1.6, and 5/3. One finds that the value of γ at which dynamical instability sets in is reduced from γ = 4/3 by rotation. One also finds that, when γ = 1.6, the normal modes of oscillation one obtains in the limit M→0 are both very far from being radial.