A&A Supplement series, Vol. 121, March 1997, 499-505

Received February 5; accepted May 21, 1996

CCD photometry of the globular cluster Palomar 13

J. Borissova - H. Markov - N. Spassova

Send offprint request: J. Borissova
Institute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko chaussèe, BG-1784 Sofia, Bulgaria

Abstract:

A new CCD photometry of the halo cluster Palomar 13 is used to construct a color - magnitude diagram in the Thuan-Gunn and the B, V photometric systems. The color-magnitude diagram of the cluster shows as already noted by Ortolani et al. (1985) an extremely poor red horizontal branch and a very sparsely populated giant branch. Seven BSS candidates are identified in the field of Palomar 13. The age of the cluster determined by fitting with the isochrones of Proffitt & Vanden Berg (1991) and Bergbusch & Vanden Berg (1992) and by a differential comparison of the color-magnitude diagram with that of Pal 5 is Gyr.

keywords: globular clusters: individual: Palomar 13 -- Hertzprung -- Russel diagram

 
• 1. Introduction
• 2. Observations and data reduction
• 3. Comparison with previous works
• Color - magnitude diagrams
• 5. The age of Palomar 13
• 6. Conclusions
• References