Spectral line asymmetries observed during stellar flares
Abstract
Stellar flares are highly energetic events occuring in stellar atmospheres. This solar-like activity has been observed on G, K and M stars. Red dwarfs usually have vast and strong magnetic fields which often reconnect and produce strong flares, sometimes classified as the so-called superflares. From spectroscopic observations we see, apart from typical enhancements of the line intensities, clearly asymmetrical line profiles. In analogy with solar flares, one would interpret them as due to flows in the flaring chromosphere. However, some stellar observations indicate a peculiar behaviour of such asymmetries and their nature is not well understood. In this work we present recent spectroscopic observations of flares on AD Leo star obtained with the Ondrejov Echelle Spectrograph. We analyze detected asymmetries using the non-LTE radiative-transfer modeling and demonstrate the importance of flare dynamics. Our interpretation is based on a close analogy with solar flares.
- Publication:
-
44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.2468W