On the role of preflares in tornado-type prominences
Abstract
We present first results of a study of rotation parameters of the tornado-type promi- nences using Hα line spectra and filtergrams. The prominences of the tornado-type were observed by ground-based spectrographs MFS and HSFA 2 in the Ondrejov Observatory (Astronomical Institute of AS CR) from 2000 to 2017. The analysis took into account the structure and dynamics of selected prominences and a comparison of the data of Hα with the EUV observations of SDO (304 Å, 193 Å, 171 Å), as well as information about the emission of flares in the X-ray range. We found that most of the analyzed events were associated with solar flares of classes from B5 to M5 by GOES classification. We revealed two types of motions in the prominences. The first type shows the Doppler velocity quasi-symmetry of the values in the "blue" and "red" Hα line wings. The events of the other type demonstrate a difference of up to one order of velocities in the direction of, and towards, the observer.
- Publication:
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Astronomical and Astrophysical Transactions
- Pub Date:
- 2019
- Bibcode:
- 2019A&AT...31..177K
- Keywords:
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- Prominences;
- solar flare