NGC 2362 is an open cluster in Canis Major, surrounding 4th magnitude star Tau Canis Majoris.
NGC 2362 was one of the discoveries of Giovanni Battista Hodierna, which he published in 1654. As these observations were forgotten until their rediscovery in the early 1980s, this cluster escaped its rediscovery until March 4, 1783, when it was found by William Herschel as his second discovery. He cataloged it as H VII.17, based on his measurements of March 6, 1785.
NGC 2362 is a bright and beautiful group containing about 60 stars in an area only 8' across. It is rich and compact, and its brightest stars are very young O- and B-type giants. NGC 2362's total integrated magnitude is 4.1, but this is heavily weighted by the brightest member of the group, τ CMa.
This star, a spectroscopic binary with very massive and luminous type O8 components, is believed to be a true cluster member. As τ CMa is the brighter component of a spectroscopic binary, its mass has been quite well determined at 40 to 50 solar masses. If τ CMa is actually a member of this cluster, as it appears, it would be one of the most luminous supergiants known, with an absolute magnitude of -7 (about 50,000 solar luminosities).
The cluster lies some 5,000 light years away; its actual diameter is about 8 light years. If we could view our own Sun from this distance, its visual magnitude would be only 15.5.
One of the youngest known star clusters, NGC 2362 may be less than 5 million years old. Dynamical studies of NGC 2362 suggest that it will survive longer before breaking up than will the Pleiades, but not as long as the Hyades.