Description
We present CCD BVI photometry for Berkeley 18, a rich open cluster located in the Galactic anticenter. The cluster age is similar to, or marginally lower than age of M 67. Its distance is estimated at 5.8kpc 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 26arcmin, which corresponds to a linear size of about 44pc. The horizontal branch of Be 18 exhibits a large width in comparison with other old open clusters.
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