Photometry of southern globular clusters. - IV. Faint photoelectric sequences in omega Centauri, NGC 6397, NGC 6752 and 47 Tucanae.
Abstract
The methods used for photometry of faint stars in star clusters are described, and the various sources of error are discussed in some detail. Faint V, B sequences, with V in the range 16.5-19, are presented in the four nearby globular clusters Omega Cen (NGC5139), NGC6397, NGC6752 and 47 Tuc (NGC 104). Thirty-five faint stars were measured in Omega Cen, and 22 stars in each of the others. These extended the brighter photoelectric sequences given in previous papers. All of the data were obtained with the same two-channel photometer on the 1.0-m telescope at Siding Spring Observatory, and are on a homogeneous system. 'Smoothed' photographic magnitudes are also given for the faint sequences.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 1981
- DOI:
- 10.1093/mnras/195.1.1
- Bibcode:
- 1981MNRAS.195....1C
- Keywords:
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- Astronomical Photometry;
- Galactic Clusters;
- Globular Clusters;
- Stellar Luminosity;
- Astronomical Photography;
- Electrophotometers;
- Error Analysis;
- Stellar Magnitude;
- Stellar Spectrophotometry;
- Astronomy;
- Globular Clusters:Photometry;
- Methods of Observation:Photometry