Serpens OB1

Sh2-54

Emission nebula
H II region
Sh2-54 nebula surrounding the star cluster NGC 6604 Credit: ESO
Observation data: J2000 epoch
Right ascension	18h 17m 53s
Declination	−11° 40′ 58″
Distance	6,200 ly
Apparent dimensions (V)	140 arcmins
Constellation	Serpens
Designations	RCW 167, Gum 84/85, W35, LBN 72
See also: Lists of nebulae

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 millions 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.

Coordinates: 18^h 17^m 53^s, −11° 40′ 58″