High Dispersion Study of Luminous Cool Stars
Abstract
We propose to obtain 16-20 hour high dispersion SWP spectra, as well as high dispersion LWR spectra, of four late-type giants. The targets are Alpha Her (M5 II + G5 III), Zeta Cyg (G8 III, Ba 0.6), Beta Peg (M2.5 II-III) and Beta And (MO IIIa). The observations of Alpha Her will extend our understanding of stellar winds, circumstellar material and binary interaction in cool stellar atmospheres. The existence of the hotter secondary star (actually a spectroscopic binary) provides a unique opportunity for studying the circumstellar material in absorption far into the ultraviolet. The observations of Zeta Cygni should present further evidence for s-enriched material in the stellar atmosphere and in the circumstellar gas and may give new information on the probable compact companion of the star and the interaction between the two components of the system. The observations of Beta Peg and Beta And should increase our knowledge dramatically as regards the dynamical state of chromospheres of M giants and lead to interesting conclusions when compared with the corresponding observations of the M supergiant Alpha Ori, and the dMe star AU Mic.
- Publication:
-
IUE Proposal
- Pub Date:
- 1983
- Bibcode:
- 1983iue..prop.1480L