The Variable Stars in the Globular Cluster NGC 6139
Abstract
Photometry is presented for ten new variables within the tidal radius of NGC 6139 and for six new variables outside the tidal radius. Of the former, five have periods indicating they are probable RR Lyrae stars; these variables seem likely to be members of the cluster. An apparent visual distance modulus for NGC 6139 of 17.2 + or - 0.4 mag is derived. The RR Lyrae stars in the cluster show period shifts appropriate to a cluster of considerably low metallicity than has been observed for NGC 6139.
- Publication:
-
The Astronomical Journal
- Pub Date:
- January 1991
- DOI:
- 10.1086/115675
- Bibcode:
- 1991AJ....101..170H
- Keywords:
-
- Blue Stars;
- Giant Stars;
- Globular Clusters;
- Stellar Spectrophotometry;
- Variable Stars;
- Light Curve;
- Metallicity;
- Stellar Magnitude;
- Astronomy;
- CLUSTERS: GLOBULAR;
- STARS: VARIABLES;
- STARS: RR LYRAE