As night falls on winter evenings, the unmistakable W of Cassiopeia suspends itself high in the north, marking a section of the sky rich in open star clusters.
One of these clusters is NGC 457, a bright object located in the rich star fields of the Cassiopeia Milky Way, about four degrees southwest of Gamma Cassiopeiae.
In the eyepiece NGC 457 appears as a scattered group of stellar points some 10′ in diameter, consisting of about 100 stars brighter than 13th magnitude. One bright foreground star, Phi Cassiopeiae, is in the middle of NGC 457 but is not a member of the cluster. A 2.4-inch telescope resolves about two dozen stars, while a 6-inch reveals almost all the stars of the cluster.
Besides its official name, NGC 457 has another one: “The ET Cluster”. To find out why, you will have to use your imagination a little. Take a close look at the NGC 457, can you see ET? Two bright stars form ET’s eyes, scattered rows of faint stars make up the arms, and the rest of the cluster forms a body.
Finder map – field width 15 degrees, stars to magnitude 8.5.