NGC 2362: Open Cluster in Canis Major

March 2009  :  Glenn Chaple

A remarkable, yet little-known open cluster is NGC 2362 which surrounds and includes the star tau Canis Majoris. This neat little stellar gathering is located three degrees east and slightly north of delta Canis Majoris. Observing guides describe NGC 2362 as a 4th magnitude object, but this figure is misleading. Much of the cluster’s brightness is taken up by tau. The rest of the 40-odd member stars are magnitude 7 to 13, and are concentrated in an area about 6 arc-minutes across. A 5000 light year distance translates to an actual diameter of 9 light years. From this distance our sun would appear as a magnitude 15.5 speck!

What makes NGC 2362 such a visual delight is its appearance in small-aperture scopes. When I look directly at tau with my 3-inch f/10 reflector, I see a handful of tiny stars around it. When I turn my gaze to the side (averted vision) the field fairly explodes with stars. It’s an amazing transformation!

Considering the fact that William Herschel was enchanted by the beauty of NGC 2362 and that Sir Patrick Moore recently included it in his Caldwell Catalog as one of the finest non-Messier objects, this cluster deserves your attention. Before Canis Major fades into the sunset, give NGC 2362 a look-see!

Your comments on this column are welcome. E-mail me at gchaple@hotmail.com.

Canis Major

When to Observe