X-ray activity of three rapidly rotating active stars using AstroSat
Abstract
We present X-ray study of three rapidly rotating active stars namely CC Eri, AB Dor, and FR Cnc is presented. A total of six flares are detected on two active stars CC Eri and AB Dor. The peak X-ray luminosities of the flares in the 0.3-7.0 keV energy band is found to be in the range of ~1031-32 erg s-1 for all flares. Spectral analysis indicates the presence of three and four temperature corona for CC Eri and AB Dor, respectively, where the highest temperature and corresponding emission meausure are found to vary along with the flare light curve. The flare-temperatures peaked at 51 - 59 MK for the flares observed in CC Eri and 29 - 44 MK for the flares from AB Dor. The abundances of the flaring plasma reached up to 0.5 and 0.7 times of the solar photospheric value for CC Eri and AB Dor, respectively. The loop-lengths for these flaring events are estimated to be of the order of 1011cm for all flares. The energy for these flaring events is estimated to be 1032-35 erg. FR Cnc was was in a quiescent state during the observations and found to be rotationally modulated with a degree of modulation of 17%. The X-ray light curve of FR Cnc was anticorrelated with optical V-band light curve.
- Publication:
-
The 20.5th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun (CS20.5)
- Pub Date:
- March 2021
- DOI:
- 10.5281/zenodo.4567669
- Bibcode:
- 2021csss.confE.268P
- Keywords:
-
- Star;
- corona;
- X-ray;
- active stars