M103, Open Cluster in Cassiopeia
The open cluster Messier 103 is often described as a Christmas tree decorated with stars (in this image,
tilted to the left). It is a physical cluster of stars which have a common proper motion (i.e., they are all
moving in the same direction and speed). The number of cluster members is thought to be about 150.
M103 is one of the more remote open clusters in Messier's catalog, at about 8,000 -9000 light years. It
is thought to be about 15 light years wide and about 25 million years old. The cluster is fairly easy to
see with binoculars in the constellation Cassiopeia.
tilted to the left). It is a physical cluster of stars which have a common proper motion (i.e., they are all
moving in the same direction and speed). The number of cluster members is thought to be about 150.
M103 is one of the more remote open clusters in Messier's catalog, at about 8,000 -9000 light years. It
is thought to be about 15 light years wide and about 25 million years old. The cluster is fairly easy to
see with binoculars in the constellation Cassiopeia.
| Location of M103 |