Open star clusters are widely distributed in our galaxy and represent a loose collection of stars which number from a few dozen to a few hundred stars and are weakly-held gravitationally. Perhaps the three most famous such open clusters are the Pleiades (M45) in Taurus, the Beehive (M44) in Cancer and the double cluster in Perseus. They are all characterized with a handful of hot and white prominent stars and nebular material surrounding these stars.

Note: The Dolidze-Dzimselejsvili open cluster catalog is comprised of eleven entries which are relatively unimpressive and generally dim with few member stars. Perhaps the most impressive entry is DoDz-9 in the constellation of Hercules which is both the largest and brightest catalog entry with an apparent diameter of 30'-35', a magnitude of 8.5 to 11 and comprised of 15 to 25 member stars.