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NGC 4111
NGC 4111 is a lenticular galaxy in the constellation Canes Venatici. It is located at a distance of circa 50 million light-years from Earth, which, given its apparent dimensions, means that NGC 4111 is about 55,000 light-years across. It was discovered by William Herschel in 1788. NGC 4111 possesses both thin and thick discs. Characteristics The galaxy is characterised by a series of dusty filaments running through its centre. They are associated with a ring of material encircling the galaxy's core, which is not aligned with the galaxy's main disc, suggesting that this polar ring of gas and dust is actually the remains of a smaller galaxy. The polar ring has a diameter of 450 pc and in it is embedded one with a diameter of 220 pc visible in H21-0 imaging. The estimated cold molecular gas mass within the polar ring is estimated to be . The ring can provide enough material for an active galactic nucleus and for circumnuclear star formation. The galaxy also possesses an X-shaped, ( ... [...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] |
Active Galactic Nucleus
An active galactic nucleus (AGN) is 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. Such excess, non-stellar emissions have been observed in the radio waves, radio, microwave, infrared, visible spectrum, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the accretion (astrophysics), accretion of matter by a supermassive black hole at the center of its host galaxy. Active galactic nuclei are the most luminous persistent sources of electromagnetic radiation in the universe and, as such, can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on cosmology, models of the cosmos. The observed characteristics of an AGN depend on several properties s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4051
NGC 4051 is an intermediate spiral galaxy in the constellation of Ursa Major. It was discovered on 6 February 1788 by John Herschel. NGC 4051 contains a supermassive black hole with a mass of 1.73 million . This galaxy was studied by the Multicolor Active Galactic Nuclei Monitoring 2m telescope. The galaxy is a Seyfert galaxy that emits bright X-rays. However, in early 1998 the X-ray emission ceased as observed by the Beppo-SAX satellite. X-ray emission had risen back to normal by August 1998. NGC 4051 is a member of the Ursa Major Cluster. Its peculiar velocity is −490 ± 34 km/s, consistent with the rest of the cluster. It is a member of the NGC 4111 Group, which is part of the Ursa Major Cloud and is the second largest group in the cloud after the NGC 3992 Group. Supernovae Three 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4013
NGC 4013 is an edge-on barred spiral galaxy about 1 E23 m, 55 million light-years away in the constellation Ursa Major. The disk of NGC 4013 shows a distinct "peanut"-shaped bulge in long exposure photographs that N-body computer simulations suggest is consistent with a stellar bar seen perpendicular to the line of sight. A recent deep color image of NGC 4013 revealed a looping Galactic tide, tidal stream of stars extending over 80 thousand light-years from the Galactic Center. This structure is thought to be the remnants of a smaller galaxy that was torn apart by tidal forces as it collided with NGC 4013. Supernova SN 1989Z was discovered on December 30, 1989 at apparent magnitude 12. NGC 4013 is a member of the Ursa Major Cluster. It is a member of the NGC 4111 Group, which is part of the Ursa Major Cloud and is the second largest group in the cloud after the NGC 3992 Group. See also * Cigar Galaxy References External links * The Discovery of a Giant Stellar Tidal Strea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3938
NGC 3938 is an unbarred spiral galaxy in the Ursa Major constellation. It was discovered by German-British astronomer William Herschel on 6 February 1788. It is one of the brightest spiral galaxies in the Ursa Major South galaxy group and is roughly 76,000 light years in diameter. It is approximately 41.4 million light years away from Earth. NGC 3938 is classified as type Sc under the Hubble sequence, a loosely wound spiral galaxy with a smaller and dimmer bulge. The spiral arms of the galaxy contain many areas of ionized atomic hydrogen gas, more so towards the center. NGC 3938 is a member of the NGC 4111 Group, which is part of the Ursa Major Cloud and is the second largest group in the cloud after the NGC 3992 Group. Supernovae and Luminous Red Nova Five supernovae have been identified within NGC 3938: * SN 1961U ( typeII, mag. 13.7) was discovered by Paul Wild on 28 December 1961. ote: some sources incorrectly list the discovery date as 2 January 1962.* SN 1964L ( ... [...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] |
NGC 4111 Group
NGC may refer to: Companies * NGC Corporation, the name of US electric company Dynegy, Inc. from 1995 to 1998 * National Gas Company of Trinidad and Tobago, a state-owned natural gas company in Trinidad and Tobago * National Grid plc, a former name of National Grid Electricity Transmission plc, the operator of the British electricity transmission system * Northrop Grumman Corporation, an aerospace and defense conglomerate formed from the merger of Northrop Corporation and Grumman Corporation in 1994 * Numismatic Guaranty Company, a coin certification company in the United States * National Garden Clubs, headquartered in St. Louis, Missouri * Network General Corporation, a defunct networking hardware company Other uses * National Gallery of Canada, an art gallery founded in 1880 in Ottawa, Canada * National Games of China, the national multi-sport event of China * National Geographic (American TV channel), a documentary and reality television channel established in the United States ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ursa Major Cluster
The Ursa Major Cluster (Ursa Major I Cluster, UMa I ClG) is a spiral-rich galaxy cluster of the Virgo Supercluster. Some of its largest members are NGC 3631, NGC 3953, M109 on North (M109 Group) and NGC 3726, NGC 3938, NGC 4051 on South. The Ursa Major cluster is located at a distance of 18.6 megaparsecs (60 million light-years) and contains about 30% of the light emitted but only 5% of the mass of the nearby Virgo Cluster The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the Virgo constellation. Comprising approximately 1,300 (and possibly up to 2,000) member galaxies, the cluster forms the heart of the larger .... Reference External links Galaxy clusters Virgo Supercluster Ursa Major {{galaxy-cluster-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Group
A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxies larger than groups that are first-order clustering are called galaxy clusters. The groups and clusters of galaxies can themselves be clustered, into superclusters of galaxies. The Milky Way galaxy is part of a group of galaxies called the Local Group. Characteristics Groups of galaxies are the smallest aggregates of galaxies. They typically contain no more than 50 galaxies in a diameter of 1 to 2 megaparsecs (Mpc).see 1022 m for distance comparisons Their mass is approximately 1013 solar masses. The spread of velocities for the individual galaxies is about 150 km/s. However, this definition should be used as a guide only, as larger and more massive galaxy systems are sometimes classified as galaxy groups. Groups are the mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chandra X-ray Observatory
The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope, enabled by the high angular resolution of its mirrors. Since the Earth's atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes; therefore space-based telescopes are required to make these observations. Chandra is an Earth satellite in a 64-hour orbit, and its mission is ongoing . Chandra is one of the Great Observatories, along with the Hubble Space Telescope, Compton Gamma Ray Observatory (1991–2000), and the Spitzer Space Telescope (2003–2020). The telescope is named after the Nobel Prize-winning Indian-American astrophysicist Subrahmanyan Chandrasekhar. Its mission is similar to that of ESA's XMM-Newton spacecraft, also launched in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
