GALACTIC CLUSTERS WITH ASSOCIATED CEPHEID VARIABLES - VI - ANONYMOUS VAN-DEN-BERGH (C0634+031) AND CV MONOCEROTIS

A photometric UBVIKC study, based upon a compilation of new and previo usly published photometry, is presented for the cluster surrounding th e 5.38 day Cepheid CV Mon. Photoelectric, photographic, and CCD observ ations are presented for 200 stars lying within similar to 8' of CV Mo n, and the data are used with spectroscopic observations for stars nea r the Cepheid to investigate the reddening and distance of cluster mem bers. The reddening law for the cluster field is described by the rela tion EU-BEB-V = 0.77, and the ratio of total to selective extinction f or the dust clouds obscuring cluster stars is characterized by R = A(V )/EB-V = 3.20 +/- 0.04 s.e. The foreground dust complex is located at a distance of similar to 900-1100 pc, whereas the cluster itself is 1. 65 +/- 0.03 kpc distant ((V-0 - M-Y) = 11.08 +/- 0.03 s.e.). CV Mon sh ares not only a spatial coincidence with cluster stars-a feature confi rmed by star counts-but also a similar radial velocity and estimated a ge. Its derived luminosity as a cluster member is (M-V)= -3.37 +/- 0.0 8 s.e., and its derived space reddening is EB-V = 0.75 +/- 0.02 [EB-V( B0) = 0.80 +/- 0.02]. There is evidence for the presence of two backgr ound groups in the held, one lying immediately beyond the cluster (d = 1.86 +/- 0.03 kpc) and a more distant group (d = 3.02 +/- 0.08 kpc). The cluster itself exhibits photometric properties-upper-main-sequence dispersion and main-sequence gaps-consistent with rapid rotation for hot cluster members. Such features are common in Cepheid-age clusters.