2000/05/31 by H. M. Antia, Antia, H. M., S. M. Chitre +3
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0005587
11 pages, A&A-LaTeX2e, to appear in Astronomy and Astrophysics
arxiv created 2000/05/31 · openalex publication_date 2000/05/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The observed splittings of solar oscillation frequencies can be employed to separate the effects of internal solar rotation and to estimate the contribution from a large-scale magnetic field or any latitude-dependent thermal perturbation inside the Sun. The surface distortion estimated from the rotation rate in the solar interior is found to be in good agreement with the observed oblateness at solar surface. After subtracting out the estimated contribution from rotation, there is some residual signal in the even splitting coefficients, which may be explained by a magnetic field of approximately 20 kG strength located at a depth of 30000 km below the surface or an equivalent aspherical thermal perturbation. An upper limit of 300 kG is derived for a toroidal field near the base of the convection zone.