IUE observations of two late type stars : R AQL and W Hya.
Abstract
Ultraviolet spectra of two late type M stars R Aql and W Hya were obtained with the International Ultraviolet Explorer (IUE). Spectra were obtained of R Aql near maximum (φ=0.21) and minimum φ=0.65) of the visible light curve. We find that the absolute flux intensity of the Mg II resonance doublet (2796 Å, 2803 Å) is essentially the same at these phases in the visible light curve. A nebular emission feature at 3133 A is detected at minimum light in R Aql that is possibly due to O III. Mg II emission is totally absent in W Hya, which contradicts earlier predictions that this star has an 8000 K permanent chromosphere. These results are discussed as they pertain to the formation of silicate grains in cool M giant atmospheres.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 1980
- Bibcode:
- 1980A&A....92..320K
- Keywords:
-
- Iue;
- Late Stars;
- Stellar Atmospheres;
- Stellar Mass Ejection;
- Stellar Spectra;
- Ultraviolet Spectra;
- Chromosphere;
- Light Curve;
- Line Spectra;
- M Stars;
- Metallic Stars;
- Stellar Winds;
- Astronomy