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: As with all open clusters, NGC 457 is best observed using widefield low- to mid-power views where, for example, the white and hot member stars provide a stunning view against the background sky. The cluster can be easily located a few degrees northeast of δ-Cassiopeiae (Ruchbach) and is best observed during late summer and early fall when it is directly overhead slightly after midnight. The two bright dominant member stars in the image below are φ1-Cas (mag 5.1) and φ2-Cas (mag 7.0). It is interesting that Messier somehow missed this stunning open cluster during his compilation of the Messier catalog and which has been described as one of the top 110 finest NGC objects to observe (see here).