Magnetically Disturbed Polytropes. III: Radial, NonRadial, Toroidal and Transverse Shear Modes of Oscillation
Abstract
The oscillations of a gaseous polytrope with a magnetic field having both a toroidal and a poloidal component are examined using the secondorder tensor virial equations on the assumption that the magnetic energy is small compared with the gravitational energy. The frequencies of oscillation of the transverse shear, the toroidal and the coupled pulsation modes are tabulated for polytropic indicesn=1, 1.5, 2, 3 and 3.5. It is found that the magnetic field decreases the frequency of oscillation of (i) the transverse shear mode and (ii) the mode which starts as a radial pulsation in the absence of a magnetic field while it increases the frequency of oscillation of (i) the toroidal mode and (ii) the Kelvin mode. In all cases the shift in frequency decreases with increasingn.
 Publication:

Astrophysics and Space Science
 Pub Date:
 March 1975
 DOI:
 10.1007/BF00646016
 Bibcode:
 1975Ap&SS..33..165S
 Keywords:

 Astronomical Models;
 Frequency Shift;
 Magnetic Field Configurations;
 Polytropic Processes;
 Vibration Mode;
 Equilibrium Equations;
 Gravitational Fields;
 Mathematical Models;
 Radial Distribution;
 Shear Properties;
 Stellar Gravitation;
 Stellar Magnetic Fields;
 Toroids;
 Transverse Oscillation;
 Astrophysics