M103

Object Type: Open Cluster
Scope: C-9.25" SCT; Exposure 55 minutes.

Messier 103 (NGC 581) is an open star cluster in Cassiopeia, discovered by Pierre Mechain in 1781. It lies roughly 8,000-10,000 light-years away and is about 25 million years old. M103 has the distinction of being the last object catalogued by Charles Messier himself in his original list.