M50

From South Dublin Astronomical Society

M50
Type	Open Cluster
NGC	NGC 2323
Constellation	Monoceros
Right Ascension	7h 02.8m
Declination	+8° 23'
Magnitude	6.3
Size	16 arc min.
Image:M50 messier image.jpg

The oft overlooked constellation of Monoceros, the Unicorn, spans a particularly rich region of the winter Milky Way. Within its boundaries there are quite a few open clusters accessible to the binocular user. Only one though, M50, made it on to Messier’s list of comet-like objects. The cluster lies midway along a line joining magnitude 3·9 Alpha Monocerotis and magnitude 4·6 Beta. Look for a slight glow studded with a handful of the group’s brighter suns. It forms a right-angled triangle with two sixth magnitude stars. M50 is about 3,000 light years away and contains some 200 members. Dimming by interstellar dust means that the true brightness of the cluster is greater than what we see and adjusting for this factor allows us to estimate its age as being somewhere around 80 million years.