HAO Colloquium - Lucia Kleint, Univ. Applied Sciences Northwestern Switzerland

The Dynamics and Magnetism of Solar Flares

Solar flares are the most energetic events on the Sun. Yet the relatively basic question “how is flare energy dissipated?” is still open. It is suspected that a large fraction of the energy of the accelerated particles is converted into continuum and line emission, heating, kinetic energy (mass motion), and changes of the magnetic field structure. By taking the “best-observed” X1 flare on 2014-03-29 as an example, I will explore what multi-wavelength observations tell us about the evolution of the solar atmosphere during a flare. Observations of the continuum at different wavelengths let us determine the flare temperature and that most of the input energy is radiated away as continuum emission. Spectroscopy and radiative transfer modeling show us mass motions, which still appear to be spatially unresolved. Chromospheric spectropolarimetry lets us determine chromospheric magnetic field changes for the first time, which intriguingly significantly differ from photospheric field changes, indicating a more complex flare picture than usually shown in the “standard model” cartoons.

Date and time: 
Wednesday, June 28, 2017 - 3:00pm to 4:00pm