Messier 25
Encyclopedia
Open Cluster M25 is an open cluster
in the constellation
Sagittarius
. It was discovered by Philippe Loys de Chéseaux in 1745 and included in Charles Messier
's list in 1764.
M25 is at a distance of about 2,000 light-year
s away from Earth
. The spatial dimension of this cluster is about 19 light years across. A Delta Cephei
type variable star
designated U Sagittarii is a member of this 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...
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....
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...
. It was discovered by Philippe Loys de Chéseaux in 1745 and included in 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"...
's list in 1764.
M25 is at a distance of about 2,000 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 away from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. The spatial dimension of this cluster is about 19 light years across. A Delta Cephei
Cepheid variable
A Cepheid is a member of a class of very luminous variable stars. The strong direct relationship between a Cepheid variable's luminosity and pulsation period, secures for Cepheids their status as important standard candles for establishing the Galactic and extragalactic distance scales.Cepheid...
type variable star
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
designated U Sagittarii is a member of this cluster.
External links
- Messier 25, The Messier Catalog. Students for the Exploration and Development of SpaceStudents for the Exploration and Development of SpaceStudents for the Exploration and Development of Space is an international student organization whose purpose is to promote space exploration and development through educational and engineering projects.-Mission statement:...
(SEDS) - Open Cluster M25. Astronomy Picture of the DayAstronomy Picture of the DayAstronomy Picture of the Day is a website provided by NASA and Michigan Technological University . According to the website, "Each day a different image or photograph of our universe is featured, along with a brief explanation written by a professional astronomer."The photograph is not necessarily...
2009 August 31