Metal-rich globular clusters in the galaxy. III. The ''X-Ray'' globular cluster NGC 6441
From a photoelectric and photographic investigation in the UBV system of the very compact, low galactic latitude, southern globular cluster NGC 6441, characteristics in the C-M diagram that are in accord with observations of the most metal-rich globular clusters in the Galaxy have been found. After an extensive discussion of the problem of isolating the cluster stars from the field stars, and of the problem of determining E (B--V), E (B--V) =0.46+-0.15 mag is adopted. If M/subV/,=+0.9 mag, then (m-M)$sub 0$=14.7+-0.3 mag. This makes NGC 6441, one of the intrinsically brightest globular clusters in the Galaxy, consistent with the large mass determined recently by Illingworth. However, no unusual features were detected in its C-M diagram that might account for its appearing within the error box of the 3U 1746--37 X-ray source, except possibly the anomalous position of V6 in the diagram. It is also found that NGC 6441 has a normal M/L ratio, and that, if our adopted reddening is correct, it is at perigalacticon. (AIP)
- Research Organization:
- Cerro Tololo Inter-American Observatory
- NSA Number:
- NSA-33-030574
- OSTI ID:
- 4031072
- Journal Information:
- Astrophys. J., v. 203, no. 1, pp. 97-112, Other Information: Orig. Receipt Date: 30-JUN-76
- Country of Publication:
- United States
- Language:
- English
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