Luminous red stars,in NGC 205.
Abstract
Blue and IR images of the center of the Local Group elliptical galaxy NGC 205 reveal a number of red stars in addition to the well-known young blue stars. Photometry of a dozen of the brightest stars in these images places the red stars between the supergiant region and the Population II giant branch in the H-R diagram. Two alternative interpretations are possible from the present data: (1) the red stars have evolved directly from a unique burst of star formation represented by the blue stars (age not less than 20-million years); and (2) NGC 205 has an extended giant branch of low-mass stars on the upper asymptotic giant branch.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1981
- DOI:
- 10.1086/183467
- Bibcode:
- 1981ApJ...244L...3G
- Keywords:
-
- Astronomical Photometry;
- Elliptical Galaxies;
- Red Giant Stars;
- Stellar Evolution;
- Stellar Luminosity;
- Asymptotic Giant Branch Stars;
- Brightness;
- Early Stars;
- Hertzsprung-Russell Diagram;
- Astronomy