Activity in late-type stars. V. Rotational modulation and flaring in UV lines on the most rapidly rotating dMe star, GL 890 (BD -16 6218).
Abstract
A series of UV spectra of GI 890 taken at two epochs separated by more than two years (on October 11-13, 1984 and on December 26, 1986) where obtained by the IUE satellite and using both the spectrograph's short-wavelength and long-wavelength cameras. Based on these data, the energy balance in the star's magnetically heated chromosphere and the transition region is investigated. Evidence for the rotational modulation of the Mg II line flux, with the maximum emission occurring close to the maximum spottedness derived from the optical light curve, is examined. A sharp dip in the Mg II flux, seen on two separate rotations is considered to be an eclipse by an unseen companion of the GI 890 star.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1990
- Bibcode:
- 1990A&A...227..490B
- Keywords:
-
- G Stars;
- Late Stars;
- M Stars;
- Stellar Activity;
- Stellar Rotation;
- Ultraviolet Spectra;
- Dwarf Stars;
- Emission Spectra;
- Iue;
- Light Curve;
- Stellar Atmospheres;
- Stellar Spectra;
- Astrophysics