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 open cluster NGC 7686 in Andromeda is a bright but poorly populated cluster comprised of at most 50 member stars which surround the bright orange star HIP 115996 (mag 6.19). It lies at a distance of 3260 light-years away with an apparent diameter of 14'. It is poorly detached from the background and which can make its observation difficult. This cluster was discovered in Herschel in 1787. NGC 7686 lies in the northeast section of Andromeda and seven degrees to the east of λ-And (mag 3.86). The cluster is best observed using low magnifications during late summer and early fall when it is placed directly overhead when looking due east.