Messier 100
Encyclopedia
Messier 100 is an example of a grand design spiral galaxy
Grand design spiral galaxy
A grand design spiral galaxy is a type of spiral galaxy with prominent and well-defined spiral arms, as opposed to multi-arm and flocculent spirals which have subtler structural features. The spiral arms of a grand design galaxy extend clearly around the galaxy through many radians and can be...

 located within the southern part of 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....

 Coma Berenices
Coma Berenices
Coma Berenices is a traditional asterism that has since been defined as one of the 88 modern constellations. It is located near Leo, to which it formerly belonged, and accommodates the North Galactic Pole...

. It is one of the brightest galaxies in the Virgo cluster
Virgo Cluster
The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly away in the constellation Virgo. Comprising approximately 1300 member galaxies, the cluster forms the heart of the larger Local Supercluster, of which the Local Group is an outlying member...

, approximately 55 million 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 distant 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...

 and has a diameter of 160,000 light years. It was discovered by Pierre Méchain
Pierre Méchain
Pierre François André Méchain was a French astronomer and surveyor who, with Charles Messier, was a major contributor to the early study of deep sky objects and comets.-Life:...

 on March 15, 1781 and was subsequently entered in Messier’s catalogue
Messier object
The Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. The original motivation of the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets...

 of nebulae and star clusters after 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"...

 made observations of his own on April 13, 1781. The galaxy was one of the first spirals discovered, and was listed as 1 of 14 spiral nebulae
Spiral galaxy
A spiral galaxy is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as...

 by Lord William Parsons of Rosse
William Parsons, 3rd Earl of Rosse
William Parsons, 3rd Earl of Rosse, Knight of the Order of St Patrick was an Irish astronomer who had several telescopes built. His 72-inch telescope "Leviathan", built 1845, was the world's largest telescope until the early 20th century.-Life:He was born in Yorkshire, England, in the city of...

 in 1850. A satellite galaxy
Satellite galaxy
A satellite galaxy orbits a larger galaxy due to gravitational attraction. Although a galaxy is made of a large number of objects which are not connected to each other, it has a center of mass, which represents a weighted average of the positions of each component object...

 named NGC 4323
NGC 4323
NGC 4323 is a galaxy about 52.5 million light-years away in the constellation Coma Berenices. It is a satellite galaxy of Messier 100....

 is present within M100.

Early observations

After the discovery of M100 by Méchain, 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"...

 made observations of the galaxy depicting it as a nebula without a star. He pointed out that it was difficult to recognize the nebula
Nebula
A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases...

 because of its faintness. William Herschel
William Herschel
Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...

 was able to identify a bright cluster of stars within the nebula during observations he did before John Herschel
John Herschel
Sir John Frederick William Herschel, 1st Baronet KH, FRS ,was an English mathematician, astronomer, chemist, and experimental photographer/inventor, who in some years also did valuable botanical work...

 expanded the findings in 1833. With the advent of better telescopes, John Herschel was able to see a round, brighter galaxy; however, he also mentioned that it was barely visible through clouds but he still indicated that it was faint. William Henry Smyth
William Henry Smyth
William Henry Smyth was an English sailor, hydrographer, astronomer and numismatist.-Private Life:...

 extended the studies of M100, detailing it as a pearly white nebula and pointing out diffuse spots.

Supernovae

Five supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

e have been identified in the M100 galaxy. In March 1901 the first supernova of M100 was found, SN 1901B
SN 1901B
SN 1901B was a supernova about 52.5 Mlys away in Messier 100, a spiral galaxy in the constellation Coma Berenices.-References:* *M100...

, a type I supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

 found when magnitude 15.6 at a distance from its nucleus. SN 1914A
SN 1914A
SN 1914A was a supernova about 52.5 Mlys away in Messier 100, a spiral galaxy in the constellation Coma Berenices.-References:* * M100...

 was then discovered in February to March 1914; its type was undeterminable but was found when magnitude 15.7 at some distance from the center. Observations of M100 from February 21, 1960 to June 17, 1960 led to the discovery of SN 1959E
SN 1959E
SN 1959E was a supernova about 52.5 Mlys away in Messier 100, a spiral galaxy in the constellation Coma Berenices.-References:* * M100...

, another type I supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

, with the faintest magnitude, 17.5, among the five found, at 58"E and 21"S from its nucleus. On April 15, 1979, the first type II supernova
Type II supernova
A Type II supernova results from the rapid collapse and violent explosion of a massive star. A star must have at least 9 times, and no more than 40–50 times the mass of the Sun for this type of explosion. It is distinguished from other types of supernova by the presence of hydrogen in its spectrum...

 found in the M100 galaxy was discovered; however the star SN 1979C
SN 1979C
SN 1979C was a supernova about 50 million light-years away in Messier 100, a spiral galaxy in the constellation Coma Berenices. The Type II supernova was discovered April 19, 1979 by Gus Johnson, a school teacher and amateur astronomer. This type of supernova is known as a core collapse and is the...

 faded quickly; later observations from x-ray to radio wavelengths revealed its remnant. The latest supernova was discovered February 7, 2006; the star SN 2006X
SN 2006X
SN 2006X was a Type Ia supernova about 65 million light-years away in Messier 100, a spiral galaxy in the constellation Coma Berenices. The supernova was independently discovered in early February 2006 by Shoji Suzuki of Japan and Marco Migliardi of Italy....

had a magnitude of 15.3 when discovered two weeks before fading to magnitude +17.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK