A&A Supplement series, Vol 121, March 1997, 455-460
Received April 11; accepted June 11, 1996
J. Kaluzny
Send offprint request: J. Kaluzny
Warsaw University Observatory, Al. Ujazdowskie 4,
00-478 Warsaw, Poland
e-mail: jka@sirius.astrouw.edu.pl
We present CCD BVI photometry for Berkeley 18, a rich
open cluster located in the Galactic anticenter.
The cluster age is similar to, or mariginally lower than age of M 67.
Its distance is estimated at 5.8 kpc and the reddening E(B-V) is
probably higher than 0.46. Our data indicate that Be 18 is one
of the most populous objects in the whole sample of known galactic
open clusters. The angular diameter of the cluster is estimated at
26 arcmin, which corresponds to a linear size of about 44 pc.
The horizontal branch of Be 18 exhibits a large width in comparison with
other old open clusters.
keywords: open clusters and associations: individual: Berkeley 18 -- HR diagram