NGC 457 -- Open Cluster in Cassiopeia
The Celestial Dragonfly
The well-known and impressive Open Cluster NGC 457 in Cassiopeia is often referred to
as the Owl or ET cluster, but that is not what comes to my mind when I view it. Being an
entomologist, believe me when I tell you it is a Celestial Dragonfly. And it is one of my
favorite Open Clusters.
NGC 457 is always a hit at star parties. Whatever image your imagination creates when
looking at the cluster, one thing is for sure -- it is one magnificent collection of stars. The
brightest star in the cluster is Phi Cassiopeiae, a type-F-supergiant. The next brightest star
(the other eye in the dragonfly) is HD 7902, a type-B-supergiant, while the orange star in
the cluster is HIP 6231, a type-M-supergiant. In the eyepiece these three magnificent
super-giants are joined by more than 200 other stars.
This Celestial Dragonfly has just laid an egg. The tiny egg is NGC 436 and is located just
behind the flying dragonfly and just out of my field-of-view in this drawing. My names for
NGC 457 (Dragonfly Cluster) and NGC 436 (Dragonfly Egg Cluster) will likely never be
accepted – but take-a-look-for-yourself and you will see that I am right!