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NGC 92
NGC 92 is a highly warped interacting unbarred spiral galaxy in Robert's Quartet; it is interacting with three neighbouring galaxies NGC 87, NGC 88 NGC 88 is a barred spiral galaxy exhibiting an inner ring structure located about 160 million light years from the Earth in the Phoenix constellation. NGC 88 is interacting with the galaxies NGC 92, NGC 87 and NGC 89. It is part of a family o ... and NGC 89. References External links * {{DEFAULTSORT:NGC 0092 0092 01388 Phoenix (constellation) Robert's Quartet Unbarred spiral galaxies 194-G012 18340930 ... [...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] |
H-alpha
H-alpha (Hα) is a specific deep-red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air and 656.46 nm in vacuum; it occurs when a hydrogen electron falls from its third to second lowest energy level. H-alpha light is the brightest hydrogen line in the visible spectral range. It is important to astronomers as it is emitted by many emission nebulae and can be used to observe features in the Sun's atmosphere, including solar prominences and the chromosphere. Balmer series According to the Bohr model of the atom, electrons exist in quantized energy levels surrounding the atom's nucleus. These energy levels are described by the principal quantum number ''n'' = 1, 2, 3, ... . Electrons may only exist in these states, and may only transit between these states. The set of transitions from ''n'' ≥ 3 to ''n'' = 2 is called the Balmer series and its members are named sequentially by Greek letters: *''n'' = 3 to ''n'' = 2 is called Balmer-alpha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Large Telescope
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m across, which are generally used separately but can be used together to achieve very high angular resolution. The four separate optical telescopes are known as ''Antu'', ''Kueyen'', ''Melipal'', and ''Yepun'', which are all words for astronomical objects in the Mapuche language. The telescopes form an array complemented by four movable Auxiliary Telescopes (ATs) of 1.8 m aperture. The VLT operates at visible light, visible and infrared wavelengths. Each individual telescope can detect objects roughly four billion times fainter than can be detected with the naked eye, and when all the telescopes are combined, the facility can achieve an angular resolution of about 0.002 arcsecond. In single telescope mode of operation angular resolution is ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, as they are subject to Perturbation (astronomy), perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or Perihelion and aphelion, aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoenix (constellation)
Phoenix is a minor constellation in the southern sky. Named after the mythical phoenix, it was first depicted on a celestial atlas by Johann Bayer in his 1603 ''Uranometria''. The French explorer and astronomer Nicolas Louis de Lacaille charted the brighter stars and gave their Bayer designations in 1756. The constellation stretches from roughly −39° to −57° declination, and from 23.5h to 2.5h of right ascension. The constellations Phoenix, Grus, Pavo and Tucana, are known as the Southern Birds. The brightest star, Alpha Phoenicis, is named Ankaa, an Arabic word meaning 'the Phoenix'. It is an orange giant of apparent magnitude 2.4. Next is Beta Phoenicis, actually a binary system composed of two yellow giants with a combined apparent magnitude of 3.3. Nu Phoenicis has a dust disk, while the constellation has ten star systems with known planets and the recently discovered galaxy clusters El Gordo and the Phoenix Cluster—located 7.2 and 5.7 billion light years away ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Galaxies Catalogue
The Catalogue of Principal Galaxies (PGC) is an astronomical catalog published in 1989 that lists B1950 and J2000 equatorial coordinates and cross-identifications for 73,197 galaxies. It is based on the Lyon-Meudon Extragalactic Database (LEDA), which was originally started in 1983. 40,932 coordinates (56%) have standard deviations smaller than . A total of 131,601 names from the 38 most common sources are listed. Available mean data for each object are given: * 49,102 morphological descriptions, * 52,954 apparent major and minor axis, * 67,116 apparent magnitudes, * 20,046 radial velocities and * 24,361 position angles. The Lyon-Meudon Extragalactic Database was eventually expanded into HyperLEDA, a database of a few million galaxies. Galaxies in the original PGC catalogue are numbered with their original PGC number in HyperLEDA. Numbers have also been assigned for the other galaxies, although for those galaxies not in the original PGC catalogue, it is not recommended to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unbarred Spiral Galaxy
An unbarred spiral galaxyAstronomy Pictures(accessed 18 April 2010) is a type of spiral galaxy without a central bar, or one that is not a barred spiral galaxy. It is designated with an SA in the galaxy morphological classification scheme. Barless spiral galaxies are one of three general types of spiral galaxies under the ''de Vaucouleurs system'' classification system, the other two being intermediate spiral galaxy An intermediate spiral galaxy is a galaxy that is in between the classifications of a barred spiral galaxy and an unbarred spiral galaxy. It is designated as SAB in the galaxy morphological classification system devised by Gerard de Vaucouleu ... and barred spiral galaxy. Under the ''Hubble tuning fork'', it is one of two general types of spiral galaxy, the other being barred spirals. Grades Unbarred lenticular galaxy An unbarred lenticular galaxy is a lenticular version of an unbarred spiral galaxy. They have the Hubble type of SA0. An example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert's Quartet
Robert's Quartet is a compact galaxy group approximately 160 million light-years away in the constellation Phoenix. It is a family of four very different galaxies whose proximity to each other has caused the creation of about 200 star-forming regions and pulled out a stream of gas and dust 100,000 light years long. Its members are NGC 87, NGC 88, NGC 89 and NGC 92, discovered by John Herschel on the 30 September 1834. The quartet is one of the best examples of compact galaxy groups. Because such groups contain four to eight galaxies in a very small region they are excellent laboratories for the study of galactic interactions and their effects, in particular on the formation of stars. The quartet has a total visual magnitude of almost 13. The brightest member of the group is NGC 92, having the blue magnitude of 13.8. On the sky, the four galaxies are all within a circle of radius of 1.6 arcmin, corresponding to about 75,000 light-years. It was named by Halton Arp and Barry F. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 87
NGC 87 is a diffuse, highly disorganized barred irregular galaxy, part of Robert's Quartet, a group of four interacting galaxies. See also * Robert's Quartet References External links NGC 87http://www.astro.pef.zcu.cz/ * {{DEFAULTSORT:NGC 0087 18340930 Barred irregular galaxies 194-8 0087 1357 Year 1357 ( MCCCLVII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. Events January–December * February 3 – The Estates General in France meets and passes Étienne Marcel's G ... Phoenix (constellation) Robert's Quartet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 88
NGC 88 is a barred spiral galaxy exhibiting an inner ring structure located about 160 million light years from the Earth in the Phoenix constellation. NGC 88 is interacting with the galaxies NGC 92, NGC 87 and NGC 89. It is part of a family of galaxies called Robert's Quartet discovered by astronomer 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 wor ... in the 1830s. References NGC 88* External links * * {{DEFAULTSORT:NGC 0088 Phoenix (constellation) 0088 01370 Robert's Quartet Barred spiral galaxies 18340930 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 89
NGC 89 is a barred spiral or lenticular galaxy, part of Robert's Quartet, a group of four interacting galaxies. This member has a Seyfert 2 nucleus with extra-planar features emitting H-alpha radiation. There are filamentary features on each side of the disk, including a jet-like structure extending about 4 kpc in the NE direction. It may have lost its neutral hydrogen (H1) gas due to interactions with the other members of the clusters—most likely NGC 92 NGC 92 is a highly warped interacting unbarred spiral galaxy in Robert's Quartet; it is interacting with three neighbouring galaxies NGC 87, NGC 88 NGC 88 is a barred spiral galaxy exhibiting an inner ring structure located about 160 million .... References External links * NGC 89* {{DEFAULTSORT:NGC 0089 0089 01374 Phoenix (constellation) Robert's Quartet Barred spiral galaxies 194-11 18340930 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC Objects
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. Sulenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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