New insight into the magnetic fields, rotation, and activity of M-dwarfs (Denis Shulyak, Gottingen University, Germany))

Strong surface magnetic fields are frequently found in spectra of
M-dwarfs, with the mean intensities
on the order of few thousand Gauss - three orders of magnitude higher
than the mean surface magnetic field
of the Sun. The appearence of such fields in both partially and fully
convective M-dwarfs provides strong constrains
on the theoretical models of stellar magnetism, because a change in
the dynamo action
in these objects is expected as well. The accurate estimates
of the magnetic field intensity and geometry in these cool objects,
however, is strongly limited to our ability to simulate the Zeeman effect in
molecular lines. In this talk I will give an overview on our modern knowledge
about properties of M dwarfs and some recently cooked results.