Deep photometry of globular clusters. VIII. The highly reddened cluster AM-2.
Abstract
Colour-magnitude diagrams for the sparse cluster AM-2 and a nearby comparison field are presented. AM-2 is situated in a rich starfield. The colour-magnitude diagram is thus seriously contaminated by field stars. However, a main sequence having a turn-off point at V ≡ 20.2 and B-V ≡ 1.04 is detected. Application of a field subtraction technique allows to derive the conclusion that AM-2 is an old cluster, intermediate between the globular cluster 47 Tucanae and the old open clusters M67 and NGC 188. AM-2 is projected in the same direction as the OB association Bochum 15. Its reddening is quite large (E(B-V) = 0.56±0.05). The distance modulus of AM-2, derived by a comparison with mean loci of other clusters, is approximately (m-M)V = 16.4±0.5, where the large uncertainty depends on the uncertain nature of the cluster. The distance is of 8.7±2.1 kpc. AM-2 is thus at 14.2±1.6 kpc from the galactic center and 0.9±0.2 kpc below the galactic plane.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- August 1988
- Bibcode:
- 1988A&AS...74..299G
- Keywords:
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- Astronomical Photometry;
- Color-Magnitude Diagram;
- Globular Clusters;
- Interstellar Extinction;
- Galactic Structure;
- Main Sequence Stars;
- Open Clusters;
- Astrophysics