Sh2-54
Sh2-54 is an extended bright nebula in the constellation of Serpens.
In its core there are many protostars and many infrared sources; some of these sources, like IRAS 18151−1208, are most probably very young high-mass stars. The older star population in this region has an average age of 4-5 million years, and its components are grouped in the open cluster NGC 6604.
Sh2-54 belongs to an extended nebulosity that includes also the Eagle Nebula and the Omega Nebula. The young high-mass stars of this region constitute the Serpens OB1 and Serpens OB2 OB association.
