Sagittarius Star Cloud
Encyclopedia
The Sagittarius Star Cloud (also known as Delle Caustiche, Messier 24, IC 4715) is a star cloud
in the constellation
of Sagittarius
, approximately 600 light years wide, which was discovered by Charles Messier
in 1764.
The stars, clusters and other objects comprising M24 are part of the Sagittarius
or Sagittarius-Carina arms of the Milky Way
galaxy. Messier described M24 as a "large nebulosity containing many stars" and gave its dimensions as being some 1.5° across, a description that fits the star cloud rather well. Some sources, improperly, identify M24 as the faint cluster
NGC 6603
.
M24 fills a space of significant volume to a depth of 10,000 to 16,000 light-year
s. This is the most dense concentration of individual stars visible using binoculars
, with around 1,000 stars visible within a single field of view
.
Star cloud
A star cloud is a group of stars that appear to be in the same position in the sky. These are not true star clusters, but rather dependent on the point of view of the observer. The stars that make up the cloud do not actually reside close to each other, they are just in the same line-of-sight.-See...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...
, approximately 600 light years wide, which was discovered by Charles Messier
Charles Messier
Charles Messier was a French astronomer most notable for publishing an astronomical catalogue consisting of deep sky objects such as nebulae and star clusters that came to be known as the 110 "Messier objects"...
in 1764.
The stars, clusters and other objects comprising M24 are part of the Sagittarius
Sagittarius Arm
The Carina–Sagittarius Arm is generally thought to be a minor spiral arm of our home galaxy, the Milky Way. Each spiral arm is a long, diffuse curving streamer of stars that radiates out from the galactic center...
or Sagittarius-Carina arms of the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
galaxy. Messier described M24 as a "large nebulosity containing many stars" and gave its dimensions as being some 1.5° across, a description that fits the star cloud rather well. Some sources, improperly, identify M24 as the faint cluster
Open cluster
An open cluster is a group of up 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 many more are thought to exist...
NGC 6603
NGC 6603
NGC 6603 is an open cluster discovered by John Herschel around 1825-33.Situated within the brightest part of star cloud M24, it is classified by Shapley as type "g". This cluster consists of about 30 stars in a field of about 5 arc minutes in diameter, and is about 9400 light years remote. Thus...
.
M24 fills a space of significant volume to a depth of 10,000 to 16,000 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s. This is the most dense concentration of individual stars visible using binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
, with around 1,000 stars visible within a single field of view
Field of view
The field of view is the extent of the observable world that is seen at any given moment....
.