M103 is one of the latest additions to the
Messier catalog. It was discovered by Pierre Mechain and
included in the catalog before Messier had a chance to observe
it directly. It was also the last object to be included in the
first publication of Messier's catalog. This is an open cluster
of stars situated in the constellation of Cassiopeia. It
consists of about 40 stars located some 8,000 light-years from
Earth. Visually, M103 is said to form an arrowhead shape. This
bright cluster is an easy target for a pair of binoculars. A
small telescope will be able to resolve the cluster's fainter
stars.
