... The bland New General Catalog designation of NGC 2237 doesn't appear to diminish the appearance of the this flowery emission nebula. Inside the nebula lies an open cluster of bright young stars designated NGC 2244 . These stars formed about four million years ago from the nebular material and their stellar winds are clearing a hole in the nebula's center, insulated by a layer of dust and hot gas. ... Publications with keywords: Rosette Nebula - NGC 2237 . ... Hot Stars in the Rosette Nebula . ...