CCD-photometry of galactic globular clusters - III. NGC 6171.
Abstract
This study presents B and V CCD photometry for 1565 stars in the low-concentration globular cluster NGC 6171 = M107. The morphology yielded by previous photometric studies is confirmed by the overall color-magnitude-diagram (CMD) properties. Metal abundance indicators derived from the CMD leading to Fe/H = - 0.89 +/-0.20, the study of the RGB intrinsic width, and the detection of the RGB bump are presented. A star count and a morphological analysis of the various branches are made, the primordial helium abundance is estimated, and the claimed lack of RGB stars and the peculiar radial distribution of RGB stars with respect to the HB ones are investigated. A description of the main sequence and an estimate of the relative age of the cluster within the scheme presented by Buonanno et al. (1989, 1990) are presented.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 1991
- DOI:
- 10.1093/mnras/252.3.357
- Bibcode:
- 1991MNRAS.252..357F
- Keywords:
-
- Color-Magnitude Diagram;
- Globular Clusters;
- Star Distribution;
- Stellar Spectrophotometry;
- Visual Photometry;
- Blue Stars;
- Charge Coupled Devices;
- Horizontal Branch Stars;
- Interstellar Extinction;
- Main Sequence Stars;
- Metallicity;
- Radial Distribution;
- Red Giant Stars;
- Tables (Data);
- Ubv Spectra;
- Astronomy