Volume 398, Number 2, February I 2003
|Page(s)||663 - 675|
|Section||Stellar structure and evolution|
|Published online||21 January 2003|
Oscillations of magnetic stars: I. Axisymmetric shear Alfvén modes of a spherical shell in a dipolar magnetic field
Laboratoire d'Astrophysique de Toulouse, Observatoire Midi-Pyrénées, 14 avenue É. Belin, 31400 Toulouse, France
2 École Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France
3 Institut Universitaire de France
Corresponding author: F. Rincon, firstname.lastname@example.org
Accepted: 5 November 2002
We carry out an investigation of axisymmetric shear Alfvén waves in a spherical layer of an incompressible resistive fluid when a strong dipolar magnetic field is applied. A decomposition on the spherical harmonics base is used to compute the eigenmodes of the system. Numerical results show that the least-damped Alfvénic modes naturally concentrate near the magnetic polar axis. These modes also show internal shear/magnetic layers associated with resonant field lines. This model is useful when modelling planetary cores sustaining a dynamo, magnetic neutron stars or to the magnetic layer of roAp stars. In this latter case, it shows that shear Alfvén waves provide a good instance of non-perturbative effects due to the strong magnetic field of such stars.
Key words: MHD / stars: oscillations / stars: magnetic fields / stars: chemically peculiar
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.