M39

From South Dublin Astronomical Society

M39
Type	Open Cluster
NGC	NGC 7092
Constellation	Cygnus
Right Ascension	21h 32.2m
Declination	+48° 26'
Magnitude	4.6
Size	32 arc min.
Image:M39 messier image.jpg

M39 lies outside the general cross-shaped pattern of Cygnus and can be found by scanning along the Milky Way from Deneb towards the Lacerta border. The cluster is nine degrees from Deneb but is so obvious that there is no risk of sweeping past without recognising it. The cluster contains a nice sprinkling of bright stars with a handful just breaking the seventh magnitude barrier. The overall impression of the group is of a blunt-nosed wedge of suns that narrows towards the direction of Deneb. Your eye will tease out other little patterns within the swarm which is quite loose. M39 is only about 800 light years away and the stars are roughly 270 million years old with some evolving towards the red giant phase. Between 50 and 100 suns are counted as members of the cluster.