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NGC 4889
NGC 4889 (also known as Caldwell 35) is an E4 supergiant elliptical galaxy. It was discovered in 1785 by the British astronomer Frederick William Herschel I, who catalogued it as a bright, nebulous patch. The brightest galaxy within the northern Coma Cluster, it is located at a median distance of 94 million parsecs (308 million light years) from Earth. At the core of the galaxy is a supermassive black hole that heats the intracluster medium through the action of friction from infalling gases and dust. The gamma ray bursts from the galaxy extend out to several million light years of the cluster. As with other similar elliptical galaxies, only a fraction of the mass of NGC 4889 is in the form of stars. They have a flattened, unequal distribution that bulges within its edge. Between the stars is a dense interstellar medium full of heavy elements emitted by evolved stars. The diffuse stellar halo extends out to one million light years in diameter. Orbiting the galaxy i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldwell 35
NGC 4889 (also known as Caldwell 35) is an E4 supergiant elliptical galaxy. It was discovered in 1785 by the British astronomer William Herschel, Frederick William Herschel I, who catalogued it as a bright, nebulous patch. The brightest galaxy within the northern Coma Cluster, it is located at a median distance of 94 million parsecs (308 million light years) from Earth. At the core of the galaxy is a supermassive black hole that heats the intracluster medium through the action of friction from infalling gases and dust. The gamma ray bursts from the galaxy extend out to several million light years of the cluster. As with other similar elliptical galaxies, only a fraction of the mass of NGC 4889 is in the form of stars. They have a flattened, unequal distribution that bulges within its edge. Between the stars is a dense interstellar medium full of heavy elements emitted by evolved stars. The diffuse stellar halo extends out to one million light years in diameter. Orbitin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type-cD Galaxy
The type-cD galaxy (also cD-type galaxy, cD galaxy) is a galaxy morphology classification, a subtype of type-D giant elliptical galaxy. Characterized by a large halo of stars, they can be found near the centres of some rich galaxy clusters. They are also known as supergiant ellipticals or central dominant galaxies. Characteristics The cD-type is a classification in the Yerkes galaxy classification scheme, one of two Yerkes classifications still in common use, along with D-type. The "c" in "cD" refers to the fact that the galaxies are very large, hence the adjective supergiant, while the "D" refers to the fact that the galaxies appear diffuse. A backformation of "cD" is frequently used to indicate "central Dominant galaxy"."Uncertainties on Clusters of Galaxies Distances", C. Adami, M.P. Ulmer, 18 July 2000, (accessed 14 April 2010) cDs are also frequently considered the largest galaxies. cD galaxies are similar to lenticular galaxies (S0) or elliptical galaxies (E#), but many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Comae Berenices
Beta Comae Berenices (β Comae Berenices, β Com) is a main sequence dwarf star in the northern constellation of Coma Berenices. It is located at a distance of about from Earth. The Greek letter beta (β) usually indicates that the star has the second highest visual magnitude in the constellation. However, with an apparent visual magnitude of 4.3, this star is actually slightly brighter than α Comae Berenices. It can be seen with the naked eye, but may be too dim to be viewed from a built-up urban area. The star is similar to the Sun, being only slightly larger and brighter in absolute magnitude. It has a stellar classification of G0 V, compared to G2 V for the Sun. The effective temperature of the outer envelope is 5,936 K, giving it a yellow hue of a G-type star. In terms of age it is younger than the Sun, being about 3 billion years old. Observations of short term variations in the chromatic activity suggest that the star undergoes differential rot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canes Venatici
Canes Venatici () is one of the IAU designated constellations, 88 constellations designated by the International Astronomical Union (IAU). It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for 'hunting dogs', and the constellation is often depicted in illustrations as representing the dogs of Boötes the Herdsman, a neighboring constellation. Cor Caroli is the constellation's brightest star, with an apparent magnitude of 2.9. La Superba (Y CVn) is one of the reddest naked-eye stars and one of the brightest carbon stars. The Whirlpool Galaxy is a spiral galaxy tilted face-on to observers on Earth, and was the first galaxy whose spiral nature was discerned. In addition, quasar Ton 618 has one of the List of most massive black holes, most massive black holes with the mass of 66 billion solar masses. History The stars of Canes Venatici are not bright. In classical times, they were listed by Ptolemy as unfigured sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patrick Moore
Sir Patrick Alfred Caldwell-Moore (; 4 March 1923 – 9 December 2012) was an English amateur astronomer who attained prominence in that field as a writer, researcher, radio commentator and television presenter. Moore was president of the British Astronomical Association; co-founder and president of the Society for Popular Astronomy; author of over seventy books on astronomy; and presenter of the world's longest-running television series with the same original presenter, BBC's ''The Sky at Night'' (from 1957). He became known as a specialist in Moon observation and for creating the Caldwell catalogue. Idiosyncrasies such as his rapid diction and monocle made him a popular and instantly recognisable figure on British television. Outside his field of astronomy, Moore was known for his role on the video game television show '' GamesMaster''. Moore was also a self-taught xylophonist and pianist, as well as an accomplished composer. He was an amateur cricketer, golfer and chess pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New General Catalogue
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William and Caroline Herschel, and John Herschel's ''General Catalogue of Nebulae and Clusters of Stars''. Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by the ''Revised New General Catalogue'' (RNGC) by Jack W. Sulent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Louis Emil Dreyer
John Louis Emil Dreyer (13 February 1852 – 14 September 1926) was a Danish astronomer who spent most of his career working in Ireland. He spent the last decade of his life in Oxford, England. Life Dreyer was born in Copenhagen. His father, Lieutenant General John Christopher Dreyer, was the Danish Minister for War and the Navy. When he was 14 he became interested in astronomy and regularly visited Hans Schjellerup at the Copenhagen observatory. He was educated in Copenhagen, taking an MA in 1872. While the same university later awarded him a PhD, in 1874. But in 1874, at the age of 22, he went to Parsonstown, Ireland. There he worked as the assistant of Lord Rosse (the son and successor of the Lord Rosse who built the Leviathan of Parsonstown telescope). During 1878 he moved to Dunsink, the site of the Trinity College Observatory of Dublin University to work for Robert Stawell Ball. In 1882 he relocated again, this time to Armagh Observatory, where he served as Director u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Catalogue Of Nebulae And Clusters Of Stars
The ''Catalogue of Nebulae and Clusters of Stars'' (CN) is an astronomical catalogue of nebulae first published in 1786 by William Herschel, with the assistance of his sister Caroline Herschel. It was later expanded into the ''General Catalogue of Nebulae and Clusters of Stars'' (GC) by his son, John Herschel. The CN and GC are the precursors to John Louis Emil Dreyer's ''New General Catalogue'' (NGC) used by current astronomers. History The ''Catalogue of Nebulae and Clusters of Stars'' was first published in 1786 by William Herschel in the ''Philosophical Transactions of the Royal Society of London''. In 1789, he added another 1,000 entries, and finally another 500 in 1802, bringing the total to 2,500 entries. This catalogue originated the usage of letters and catalogue numbers as identifiers. The capital "H" followed with the catalogue entry number represented the item. In 1864, the CN was expanded into the ''General Catalogue of Nebulae and Clusters of Stars'' (GC) by John H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical work. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus – the seventh planet, discovered by his father Sir William Herschel. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays. His ''Preliminary Discourse'' (1831), which advocated an inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science. Early life and work on astronomy Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and astronomer William Herschel. He was the nephew of astronomer Caroline Herschel. He studied shortly at Eton College an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalogue Of Nebulae And Clusters Of Stars
The ''Catalogue of Nebulae and Clusters of Stars'' (CN) is an astronomical catalogue of nebulae first published in 1786 by William Herschel, with the assistance of his sister Caroline Herschel. It was later expanded into the ''General Catalogue of Nebulae and Clusters of Stars'' (GC) by his son, John Herschel. The CN and GC are the precursors to John Louis Emil Dreyer's ''New General Catalogue'' (NGC) used by current astronomers. History The ''Catalogue of Nebulae and Clusters of Stars'' was first published in 1786 by William Herschel in the ''Philosophical Transactions of the Royal Society of London''. In 1789, he added another 1,000 entries, and finally another 500 in 1802, bringing the total to 2,500 entries. This catalogue originated the usage of letters and catalogue numbers as identifiers. The capital "H" followed with the catalogue entry number represented the item. In 1864, the CN was expanded into the ''General Catalogue of Nebulae and Clusters of Stars'' (GC) by John H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caroline Herschel
Caroline Lucretia Herschel (; 16 March 1750 – 9 January 1848) was a German born British astronomer, whose most significant contributions to astronomy were the discoveries of several comets, including the periodic comet 35P/Herschel–Rigollet, which bears her name.Nysewander, Melissa. Caroline Herschel. Biographies of Women Mathematicians, Atlanta: Agnes Scott College, 1998. She was the younger sister of astronomer William Herschel, with whom she worked throughout her career. She was the first woman to receive a salary as a scientist and the first woman in England to hold a government position. She was also the first woman to publish scientific findings in the ''Philosophical Transactions'' of the Royal Society, to be awarded a Gold Medal of the Royal Astronomical Society (1828), and to be named an Honorary Member of the Royal Astronomical Society (1835, with Mary Somerville). She was named an honorary member of the Royal Irish Academy (1838). The King of Prussia presented h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier Catalogue
The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his ''Catalogue des Nébuleuses et des Amas d'Étoiles'' (''Catalogue of Nebulae and Star Clusters''). Because Messier was only interested in finding comets, he created a list of those non-comet objects that frustrated his hunt for them. The compilation of this list, in collaboration with his assistant Pierre Méchain, is known as ''the Messier catalogue''. This catalogue of objects is one of the most famous lists of astronomical objects, and many Messier objects are still referenced by their Messier numbers. The catalogue includes most of the astronomical deep-sky objects that can easily be observed from Earth's Northern Hemisphere; many Messier objects are popular targets for amateur astronomers. A preliminary version first appeared in 1774 in the ''Memoirs'' of the French Academy of Sciences for the year 1771. The first version of Messier's catalogue contain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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