2004/03/13 by S. B. F. Dorch · 1 citation
Physics and Astronomy · #Action (physics) #Astro and Planetary Science #Astrophysics and Star Formation Studies #Dynamo #Dynamo theory #Field (mathematics) #Magnetic field #Magnetohydrodynamics #Solar dynamo #Stellar, planetary, and galactic studies #Supergiant #astro-ph
paper · pdf · doi:10.1051/0004-6361:20040435
published as Astron.Astrophys. 423 (2004) 1101-1107 · 7 pages, 9 figures (2 in color), submitted to A&A
arxiv created 2004/03/13 · openalex publication_date 2004/08/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Evidence is presented from numerical magneto-hydrodynamical simulations for the existence of magnetic activity in late-type giant stars. A red supergiant with stellar parameters similar to that of Betelgeuse (α Orionis) is modeled as a “star-in-a-box” with the high-order “Pencil Code”. Both linear kinematic and non-linear saturated dynamo action are possible: the non-linear magnetic field saturates at a super-equipartition value corresponding to surface magnetic field of field strengths up to ~500 Gauss. In the linear regime two different modes of dynamo action are found with exponential growth rates of ~4 and 25 years, respectively. It is speculated that magnetic activity of late-type giants may influence dust and wind formation and possibly lead to the heating of the outer atmospheres of these stars.