Deep CCD Photometry and Variable Stars in the Metal-Rich Globular Cluster M71
Abstract
Two sets of observations of the metal-rich globular cluster M71 are presented. The first uses deep CCD exposures to derive a fiducial in V, B - V and compares this with a cluster of similar metallicity, 47 Tuc. Comparison with oxygen enhanced theoretical isochrones leads to age estimates for M71 of from about 14 +/- 2 Gyr to about 16 +/- 2 Gyr. Within the limits imposed by the quality of the data, no significant age difference between the two clusters is found. The second set of 73 frames is used to search an overlapping 67 x 104 arcsec area of the cluster for variable stars.
- Publication:
-
The Astronomical Journal
- Pub Date:
- February 1992
- DOI:
- 10.1086/116075
- Bibcode:
- 1992AJ....103..460H
- Keywords:
-
- Astronomical Photometry;
- Globular Clusters;
- Metallicity;
- Variable Stars;
- Color-Magnitude Diagram;
- Galactic Evolution;
- Light Curve;
- Stellar Evolution;
- Astrophysics;
- GLOBULAR CLUSTERS: M71;
- STARS: VARIABLES;
- INSTRUMENTATION: PHOTOMETERS