Messier 103 (also catalogued as NGC 581) is an open cluster in the constellation Cassiopeia. Discovered in 1781 by Charles Messier’s collaborator Pierre Méchain, it is one of the most distant open clusters, with distances of 8,000 to 9,500 light years from the Earth. In space the cluster ranges about 15 light years apart. Observations of M103 are generally dominated by the appearance of the triple star Struve 131, which is the bright star at the north vertex of the cluster (left on the image), though this star is not a member of the 172-star cluster. The age of M103 is estimated to be about 25 million years.. This image was taken remotely from the remote controlled IRIDA Observatory .