SCYON Abstract

Received on November 22 2001

A deep VI CCD photometric study of the neglected galactic star cluster NGC 6631

Authors	Ram Sagar, B.N. Naidu and V. Mohan
Affiliation	Indian Institute of Astrophysics, Bangalore - 560 034, India, State Observatory, Manora Peak, Nainital - 263 129, India
To appear in	Bull. Astron. Soc. India
Contact	sagar@upso.ernet.in
URL	http://upso.ernet.in
Links	NGC 6631

Abstract

We present the VI CCD photometric observations of about 5500 stars up to a limiting magnitude of V ~ 20 in an area of ~16' x 16' around the cluster NGC 6631. The cluster parameters determined for the first time by fitting the theoretical isochrones in the (V, V-I) diagram of the cluster stars are E(V-I) = 0.60 ± 0.05$ ± mag, distance = 2.6 ± 0.5 kpc, age = 400 ± 100 Myr and metallicity, Z = 0.05. The cluster diameter determined from the radial density profile is 4.8 ± 0.5 pc. The mass function of the cluster has a slope of 2.1 ± 0.5.