Sh 2-54 is an extended
bright nebula
A nebula (; or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral, or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as in the Pillars of Creation in th ...
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
A protostar is a very young star that is still gathering mass from its parent molecular cloud. It is the earliest phase in the process of stellar evolution. For a low-mass star (i.e. that of the Sun or lower), it lasts about 500,000 years. The p ...
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
NGC 6604 is a young open cluster of stars in the equatorial constellation of Serpens, positioned about 1.5° north of the Eagle Nebula (NGC 6611). The cluster was discovered by William Herschel on July 15, 1784. It is located at a distance of 4 ...
.
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 Omega Nebula is an H II region in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745. Charles Messier catalogued it in 1764. It is by some of the richest starfields of the Milky Way, figuring in the north ...
. The young high-mass stars of this region constitute the Serpens OB1 and Serpens OB2
OB association
The Ob (; ) is a major river in Russia. It is in western Siberia, and with its tributary the Irtysh forms the world's seventh-longest river system, at . The Ob forms at the confluence of the Biya and Katun which have their origins in the Al ...
.
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