NGC 2237, 2238, 2239, and 2246 (Rosette Nebula)

Constellation: Monoceros

Distance: 5,000 light years

One of the finest H2 regions in the northern sky, the Rosette Nebula is one of the largest in our galaxy, measuring approximately 130 light years across and containing enough gas and dust to form 10,000 stars. A young open cluster designated NGC 2244 can be seen emerging at the nebula's center, composed of about 100 stars over only a half degree of sky. The radiation pressure and stellar winds from these stars have excavated the center of the nebula and their ultraviolet light ionizes and excites the surrounding emission cloud.