Sh 2-310
Sh 2-310 is a nebula in Canis Major. It is one of the largest H II regions known in the Milky Way. It is ionized by the stars Tau [Canis Majoris] and UW Canis Majoris. The red hypergiant VY Canis Majoris is located near the nebula's rim and the open cluster NGC 2362 is located near the nebula.