### CCD UBVRI Photometry of the Galactic open clusters: Be 89, Ru 135, and Be 10

#### Abstract

The fundamental parameters of reddening, metallicity, age, and distance are presented for the poorly studied open clusters Be 89, Ru 135, and Be 10, derived from their CCD UBVRI photometry. The interstellar reddenings, E(B–V ), were measured in the two-color diagram, and the photometric metallicities, [Fe/H], from the ultraviolet excesses of the F-type stars. By fitting isochrones to the observed sequences of the clusters in five different color-magnitude diagrams, the weighted averages of distance moduli and heliocentric distances [(V0–MV ), d(kpc)] are (11.m 90 ± 0.m 06, 2.4 ± 0.06) for Be 89, (9.m 58 ± 0.m 07, 0.81 ± 0.03) for Ru 135, and (11.m 16 ± 0.m 06, 1.7 ± 0.05) for Be 10, and the weighted averages of the ages [log(A),A(Gyr)] are (9.58 ± 0.06, 3.8 ± 0.6) for Be 89, (9.58 ± 0.06, 3.8 ± 0.7) for Ru 135, and (9.06 ± 0.05, 1.08 ± 0.08) for Be 10.

#### Keywords

open clusters and associations: individual (Be10, Be89, Ru135); stars: fundamental parameters; stars: Hertzsprung-Russell and C-M diagrams; techniques: photometric