A Cool Giant with a Circumstellar Cloud
Kondo, Y.; Gurzadian, G. A.; Perez, Mario R.; Terzian, Yervant; Okhanesian, I. B.
Armenia, United States
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) MgII 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 MgII emission at 2800. The absorption cores on the peaks of the emission profiles MgIIk andh are mainly of interstellar origin and only partly — due to self-absorption in the star's chromosphere.