Fossil fields in Ap/Bp stars: an origin from star formation and protostellar evolution

• Applicants: Professor Dr. Robi Stefan Banerjee; Dr. Petri Käpylä
• Subject Area: Astrophysics and Astronomy
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 550644508

A significant fraction of Ap/Bp stars, i.e. peculiar intermediate-mass main-sequence stars, host strong magnetic fields from 200 G up to 20 kG. Although, those stars could generate magnetic fields via dynamo activity in the convective core, it is not very likely that this dynamo mechanism is effective enough to be responsible for the observed, fairly strong magnetic fields in Ap/Bp stars. Hence, it is more likely that these magnetic fields are of 'fossil' origin, i.e. being trapped during the formation of the stars. In this project, our goal is to significantly advance in our understanding of the origin of fossil fields in Ap/Bp stars through a quantitative exploration of the connection between star formation, protostellar evolution and its impact on the magnetic fields. These studies will be based on state-of-the art numerical simulations, of the magnetised star formation history as well as the long-term evolution of magnetic fields in fully convective core.

• DFG Programme: Research Grants
• International Connection: Chile, Italy
• Cooperation Partners: Professor Dr. Daniele Galli; Professor Dr. Dominik R.G. Schleicher