Sh 2-54 is an extended
bright nebula in the
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The first constellati ...
of
Serpens
Serpens () is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations designated by the International Astronomical Union. It ...
.
In its core there are many
protostars and many
infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...
sources; some of these sources, like
IRAS
The Infrared Astronomical Satellite (Dutch language, Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a astronomical survey, survey of the entire night sky at infrared wavelengths. Launched on 25 Janu ...
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
An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
NGC 6604.
Sh 2-54 belongs to an extended nebulosity that includes also the
Eagle Nebula
The Eagle Nebula (catalogued as Messier 16 or M16, and as NGC 6611, and also known as the Star Queen Nebula) is a young open cluster of stars in the constellation Serpens, discovered by Jean-Philippe de Cheseaux in 1745–46. Both the "Eagle" a ...
and the
Omega Nebula. The young high-mass stars of this region constitute the Serpens OB1 and Serpens OB2
OB association.
Gallery
Image:Serpent%E2%80%99s_Nebula.jpg, Serpent's Nebula
See also
*
H II region
An H II region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light year ...
References
External links
Sky-Map.org – Sharpless Catalogue (from 51 to 60)
{{DEFAULTSORT:Sh 2-54
H II regions
Serpens
054
Star-forming regions
Stellar associations