2007/04/11 by Jonathan Braithwaite, J. Braithwaite
Earth and Planetary Sciences · Physics and Astronomy · #Geophysics and Gravity Measurements #Pulsars and Gravitational Waves Research #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.1051/0004-6361:20065903
A&A accepted. Animations available at http://www.cita.utoronto.ca/~jon/research/rp_anims.html
openalex publication_date 2007/04/11 · arxiv created 2007/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The stability of large-scale magnetic fields in rotating stars is explored, using 3D numerical hydrodynamics to follow the evolution of an initial poloidal field. It is found that the field is subject to an instability, located initially on the magnetic equator, whereby the gas is displaced in a direction parallel to the magnetic axis. If the magnetic axis is parallel to the rotation axis, the rotation does not affect the initial linear growth of the instability, but does restrict the growth of the instability outside of the equatorial zone. The magnetic energy decays on a timescale which is a function of the Alfvén crossing time and the rotation speed, but short compared to any evolutionary timescale. No evidence is found for a possible stable end state to evolve from an initial axisymmetric poloidal field. The field of an oblique rotator is similarly unstable, in both cases regardless of the rotation speed.