Astronomy Seminars

Giant magnets in small stars. New insights into multi-scale nature of M-dwarf magnetic fields

by Prof. Oleg Kochukhov (Uppsala University)

FC61 (AlbaNova Main Building)


AlbaNova Main Building

Zoom ID: 622 1126 9644

Magnetic fields play a fundamental role for the interior and atmospheric properties of M dwarfs and greatly influence terrestrial planets orbiting in the habitable zones of these low-mass stars. Determination of the strength and topology of magnetic fields, both on stellar surfaces and throughout the extended stellar magnetospheres, is a key ingredient for advancing stellar and planetary sciences. In this talk I will review magnetic field measurements applied to M dwarfs, with the emphasis on direct methods based on interpretation of the Zeeman effect signatures in high-resolution intensity and polarisation spectra. I will summarise results of the field strength measurements using Zeeman broadening studies as well as information on the global magnetic geometries inferred from spectropolarimetric observations. The emerging understanding of complex, multi-scale nature of M-dwarf magnetic fields will be discussed in the context of theoretical models of hydromagnetic dynamos and stellar interior structure altered by magnetic fields.

Zoom ID: 622 1126 9644