M103 (NGC 581), Open Cluster in Cassiopeia
LRGB combination (Click for a larger view 1800 x 1800 px)
M103 (NGC 581), Open Cluster type 'd', in Cassiopeia
Discovered by Pierre Mechain in 1781.
Messier 103 (also known as M103, or NGC 581) is an open cluster where a few thousand stars formed in the constellation Cassiopeia.It is one of the "latest additions" (together with M101 and 102) to his catalog, which Charles Messier included from Pierre Mechain's report. The number of proven cluster members has been given as 40 by Wallenquist, while Becvar has 60, and Archinal and Hynes (2003) give a modern number of 172 member stars. M103 is one of the more remote open clusters in Messier's catalog, at about 8000 to 9500 light years and ranging about 15 light years apart. M103 is about 25 million years old.
All Contents copyright © Velimir Popov unless otherwise noted.