CCD PHOTOMETRY OF THE GLOBULAR CLUSTER NGC 5897

Abstract

We report CCD photometric observations of the globular cluster NGC 5897, in the Johnson system filters B, V, R, and I. With the values for these magnitudes we obtain various colour indices and produce several colour-magnitude diagrams. We present eight colour-magnitude diagramas: V vs B - V, B vs B - V, V vs V - I, I vs V - I, R vs R - I, I vs R - I, V vs V - R, and R vs V - R. In all of these diagrams we can clearly see the Giant Branch, the Horizontal Branch and the beginning of the Main Sequence. To the left of the Main Sequence turn-off point we detect a somewhat large number of Blue Straggler stars. We determine the mean value of the visual magnitude of the HB as 16.60 ± 0.46. This value is fainter than the value found by other authors.