A spectral study of the active giant OP And in the period 1979 - 2010
Abstract
We present a study of the activity indicators of the single giant star OP And. Spectral data obtained with the Coudé spectrograph of the 2m telescope of Rozhen National Astronomical Observatory in Bulgaria and from Narval at the 2-m Telescope Bernard Lyot (TBL), Pic du Midi Observatory, France, as well as data from the literature are used in order to study the long-term behaviour of H_α, CaII H&K, and CaII IR triplet lines. The star has periods with variable activity. The intensity of the CaII H&K emission lines and the partially filled-in by emission H_α absorption core vary in time. OP And was on the higher activity level up to 1996, but for 2008 and 2010 it had a lower activity stage. This fact supports the idea that the mass outflow in OP And is controlled by the magnetic field.
- Publication:
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Bulgarian Astronomical Journal
- Pub Date:
- June 2012
- Bibcode:
- 2012BlgAJ..18b..27B
- Keywords:
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- Stars: activity;
- Stars:individual:OP And;
- Line: profiles