Study of faint young open clusters as tracers of spiral features in our Galaxy

Abstract

Continuing the study of faint young open clusters as tracers of spiral features in the Galaxy, photoelectric and photographic photometry of 39 stars was done in the field of the faint open cluster NGC 2236 = OCl 501 in the direction of Monoceros constellation. Out of these stars, a total of 22 down to m(v) equal to about 15.4 mag have been found to be probable members. There is apparently a variable extinction across the field of the cluster with E(B-V) ranging between 0.84 mag and 0.68 mag. The median age of this cluster is estimated to be 7.6 x 10 exp 7 years, and the cluster is thereby considered as belonging to the marginally old category. Thus, it cannot be specifically used as a spiral arm tracer in the study of the Galaxy. This cluster is located at a distance of 3.72 +/- 0.13 kpc, which places it at the inner edge of the outer Perseus spiral feature of the Milky Way.