A Cool Giant with a Circumstellar Cloud
Abstract
The IUE spectrum of the star HD 139521, a giant of class G8III is obtained and based on the analysis of the narrow structure of 2795 (k) and 2803 (h) Mg II emission profiles, the existence of a circumstellar cloud around the giant star is assumed. This conclusion is confirmed also by the anomaly of the small observed power of the doublet Mg II emission at 2800. The absorption cores on the peaks of the emission profiles Mg II k andh are mainly of interstellar origin and only partly — due to self-absorption in the star's chromosphere.
- Publication:
-
Astrophysics and Space Science
- Pub Date:
- February 1991
- DOI:
- 10.1007/BF00643077
- Bibcode:
- 1991Ap&SS.176...61G
- Keywords:
-
- Emission Spectra;
- Giant Stars;
- Stellar Envelopes;
- Stellar Spectra;
- Absorption Spectra;
- Fine Structure;
- G Stars;
- Magnesium;
- Ultraviolet Spectra;
- Astrophysics