Beate Stelzer (Tübingen)

Hot side up: the outer atmospheres of cool stars
When Feb 21, 2019 from 02:30 PM to 03:30 PM
  • Colloquium
Where SH Lecture Hall
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The outer atmospheres of low-mass star are heated by the stellar magnetic field. The radiation from these hot parts of the stellar atmosphere comprises optical emission lines, UV and X-ray radiation, and is collectively termed `magnetic activity'. Our knowledge of these processes is especially poor for the lowest-mass stars, the M dwarfs, where the solar-type dynamo mechanism breaks down. I present a series of ongoing studies on the multi-wavelength observational characterization of the dynamic outer atmospheres of M dwarf stars. The direct aim of such studies is to understand (i) the influence of the magnetic field on the radiative output of the star, i.e. how the stellar dynamo works, (ii) the connection between stellar activity, rotation and age, as a probe of angular momentum evolution, and (iii) the role that the stellar high energy (UV and X-ray) radiation plays in the evolution of circumstellar disks and planet atmospheres.