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NGC 3913
NGC3913 is a spiral galaxy in the constellation of Ursa Major. Its velocity with respect to the cosmic microwave background for is , which corresponds to a Hubble distance of . However, three ''non redshift'' measurements give a much closer distance of . It was discovered by German-British Astonomer William Herschel on 14 April 1785. It was also observed by Lewis Swift on 8 May 1890, which resulted in the galaxy also being listed in the Index Catalogue as ''IC 740''. The SIMBAD database lists NGC 3913 as an Active Galaxy Nucleus Candidate, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. NGC 3631 Group According to A.M. Garcia, NGC 3913 is part of the NGC 3631 group (also known as LGG 241). This group includes at least 10 galaxies, including NGC 3631, NGC 3657, NGC 3718, NGC 3729, NGC 3972, NGC 3998, UGC 62 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fritz Zwicky
Fritz Zwicky (; ; February 14, 1898 – February 8, 1974) was a Swiss astronomer. He worked most of his life at the California Institute of Technology in the United States of America, where he made many important contributions in theoretical and observational astronomy. In 1933, Zwicky was the first to use the virial theorem to postulate the existence of unseen dark matter, describing it as "'". From p 125: ''"Um, wie beobachtet, einen mittleren Dopplereffekt von 1000 km/sek oder mehr zu erhalten, müsste also die mittlere Dichte im Comasystem mindestens 400 mal grösser sein als die auf Grund von Beobachtungen an leuchtender Materie abgeleitete. Falls sich dies bewahrheiten sollte, würde sich also das überraschende Resultat ergeben, dass dunkle Materie in sehr viel grösserer Dichte vorhanden ist als leuchtende Materie."'' (In order to obtain an average Doppler effect of 1000 km/s or more, as observed, the average density in the Coma system would thus have to be at least 40 ... [...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 galaxy, 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 Herschel, William and Caroline Herschel, and John Herschel's ''General Catalogue of Nebulae and Clusters of Stars''. Objects south of the Celestial sphere, 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 Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3718
NGC 3718, also called Arp 214, is a galaxy located approximately 52 million light years from Earth in the constellation Ursa Major. Near NGC 3718 is the galaxy NGC 3729, a peculiar barred spiral galaxy. It is either a lenticular or spiral galaxy. NGC 3718 exhibits a warped, S-shape similar to NGC 6872, possibly a result of gravitational interaction with NGC 3729, another spiral galaxy located 150,000 light-years away. The Hickson Compact Group 56 can be seen south of one of NGC 3718's spiral arms. HCG 56 is 8 times more far then NGC 3718 or NGC 3729 NGC 3718 is a member of the Ursa Major Cluster. Hickson Compact Group South of NGC 3718 the Hickson Compact Group #56 is located. HCG 56 is a compact group of galaxies of which 4 members are interacting with each other. This group is about 120 Mpc distant to our galaxy, which is about 8 times more distant than NGC 3718. Gallery File:NGC 3718 with NGC 3729.jpg, NGC 3718 and its companion NGC 3729. File:NGC 3718 legacy dr1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of NGC Objects (3001–4000)
This is a list of NGC objects 3001–4000 from the New General Catalogue (NGC). The astronomical catalogue is composed mainly of star clusters, nebulae, and galaxies. Other objects in the catalogue can be found in the other subpages of the list of NGC objects. The constellation information in these tables is taken from ''The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer'', which was accessed using the "VizieR Service". Galaxy types are identified using the ''NASA/IPAC Extragalactic Database''. Other data are from the SIMBAD Astronomical Database unless otherwise stated. 3001–3100 3101–3200 3201–3300 3301–3400 3401–3500 3501–3600 3601–3700 3701–3800 3801–3900 3901–4000 See also * Lists of astronomical objects This is a list of lists, grouped by type of astronomical object. Solar System * List of Solar System objects * List of gravitationally rounded objects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sloan Digital Sky Survey
The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project began in 2000 and was named after the Alfred P. Sloan Foundation, which contributed significant funding. A consortium of the University of Washington and Princeton University was established to conduct a redshift survey. The Astrophysical Research Consortium (ARC) was established in 1984 with the additional participation of New Mexico State University and Washington State University to manage activities at Apache Point. In 1991, the Sloan Foundation granted the ARC funding for survey efforts and the construction of equipment to carry out the work. Background At the time of its design, the SDSS was a pioneering combination of novel instrumentation as well as data reduction and storage techniques that drove major advances in astronomical observations, dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most versatile, renowned as a vital research tool and as a public relations boon for astronomy. The Hubble Space Telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories program, Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible spectrum, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of atmosphere of Earth, Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels, Belgium and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. the Union had 85 national members and 12,734 individual members, spanning 90 countries and territories. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Wild (Swiss Astronomer)
Paul Wild (; 5 October 1925 – 2 July 2014) was a Swiss astronomer and director of the Astronomical Institute of the University of Bern, who discovered numerous comets, asteroids and supernovae. Biography Wild was born on 5 October 1925 in the village of Wädenswil near Zürich, Switzerland. From 1944 through 1950, he studied mathematics and physics at the ETH Zurich. Thereafter, he worked at the California Institute of Technology where he researched galaxies and supernovas under the leadership of countryman Fritz Zwicky from 1951 through 1955. At the Zimmerwald Observatory, near Bern, Wild made his first cometary discovery C/1957 U1 (1957 IX) on 2 October 1957. The parabolic comet was later named "Latyshev-Wild– Burnham". Professor Wild became director of the Astronomical Institute of the University of Bern in 1980, and remained in this position until 1991. He died on 2 July 2014 at the age of 88 in Bern. Discoveries During countless nights Wild observed the ski ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Ia Supernova
A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white dwarf. Physically, carbon–oxygen white dwarfs with a low rate of rotation are limited to below 1.44 solar masses (). Beyond this "Chandrasekhar limit, critical mass", they reignite and in some cases trigger a supernova explosion; this critical mass is often referred to as the Chandrasekhar mass, but is marginally different from the absolute Chandrasekhar limit, where electron degeneracy pressure is unable to prevent catastrophic collapse. If a white dwarf gradually accretes mass from a binary companion, or merges with a second white dwarf, the general hypothesis is that a white dwarf's core will reach the ignition temperature for Carbon burning process, carbon fusion as it approaches the Chandrasekhar mass. Within a few seconds of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova
A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the ''progenitor'', either collapses to a neutron star or black hole, or is completely destroyed to form a diffuse nebula. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months. The last supernova directly observed in the Milky Way was Kepler's Supernova in 1604, appearing not long after Tycho's Supernova in 1572, both of which were visible to the naked eye. The supernova remnant, remnants of more recent supernovae have been found, and observations of supernovae in other galaxies suggest they occur in the Milky Way on average about three times every century. A supernova in the Milky Way would almost certainly be observable through mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M109 Group M109.
The M109 Group (also known as the NGC 3992 Group or Ursa Major cloud) is a group of galaxies about 55 million light-years away in the constellation Ursa Major. The group is named after the brightest galaxy within the group, the spiral galaxy Spiral galaxies form a galaxy morphological classification, class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae'' 
Members The table below lists galaxies that have been consistently identified as group members in the Nearby Galaxies Catalog, the survey of Fouque et al.,[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
