Magnetic flux emergence across the Hertzsprung-Russell diagram

• Applicant: Dr. Rainer Arlt
• Subject Area: Astrophysics and Astronomy
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 224559602

The observations of starspots by photometric and spectroscopic methods as well as the detection of magnetic fields on a variety of stars motivates numerical studies of how magnetic flux emerges at the surfaces of these stars. This project aims at the numerical simulation of magnetic flux-rise in a wide range of stars with convective envelopes with emphasis on young dwarfs. Their faster rotation delivers suitable observational material for comparisons. The computations will employ magnetic-field distributions expected from state-of-the-art mean-field models as well as the differential rotation expected from models of rotating convection. The proposed simulations will complement the experience gathered on the problem of magnetic flux-rise in the solar convection zone.Compressible models as the ones propose here, are a must for convective envelopes of red giants in which convective velocities are no longer very small compared to the sound speed. We therefore focus not only on the early evolution of dwarf stars, but on the starspot emergence on giants as well.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Klaus G. Strassmeier