M46

From South Dublin Astronomical Society

M46
Type	Open Cluster
NGC	NGC 2437
Constellation	Puppis
Right Ascension	7h 41.8m
Declination	-14° 49'
Magnitude	6.1
Size	27 arc min.
Image:M46 messier image.jpg

You’ll never tire of the pairing of the two open clusters M46 and M47. The duo are in northern Puppis, set in a rich winter Milky Way field. The easiest way to find them is probably to scan three binocular field widths east from brilliant Sirius and just nudge your instruments a little north after the final “hop”. The sight is dramatic with M46, to the east (left), showing as a milky blur of light studded with the brighter members of the group. M47 on the other hand is much looser and beautifully resolved. It’s one of the finest deep sky sights for binoculars and well worth spending a little time absorbing the view. Just 2½º above the pair is Melotte 71, a much more distant cluster that appears as an indistinct smear of light. The two clusters are not physically associated though; M46 is 5,400 lights years away while M47 is a little closer at 5,200 light years.