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LEDA 135657
LEDA 135657 is a distant low surface brightness spiral galaxy located about 570 million light-years away in the constellation Cetus. It has an estimated diameter of 97,000 light-years. See also * Malin 1 a giant low surface brightness galaxy discovered in 1986 * NGC 45 * Low-surface-brightness galaxy A low-surface-brightness galaxy, or LSB galaxy, is a diffuse galaxy with a surface brightness that, when viewed from Earth, is at least one magnitude lower than the ambient night sky. Most LSBs are dwarf galaxies, and most of their baryonic mat ... References External links Spiral galaxies Cetus (constellation) 135657 Low surface brightness galaxies {{Spiral-galaxy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyon-Meudon Extragalactic Database
The Lyon-Meudon Extragalactic Database (LEDA) was a database of galaxies, created in 1983 at the Lyon Observatory. Each galaxy had a number assigned to it, which is now known as its PGC number. The 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), ... (PGC), published in 1989, was based on the Lyon-Meudon Extragalactic Database and contained cross-identifications for it. LEDA was eventually merged with Hypercat to become HyperLEDA in 2000, itself also known as PGC2003. LEDA originally contained information on more than 60 parameters for about 100,000 galaxies, and now contains information on over 3 million celestial objects, of which about 1.5 million are galaxies. The database allows astronomers around the world access to its information. References ... [...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] |
Light-year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry; it is the distance at which one astronomical unit subtends an angle of one second of arc. Defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cetus (constellation)
Cetus () is a constellation, sometimes called 'the whale' in English. The Cetus was a sea monster in Greek mythology which both Perseus and Heracles needed to slay. Cetus is in the region of the sky that contains other water-related constellations: Aquarius, Pisces and Eridanus. Features Ecliptic Cetus is not among the 12 true zodiac constellations in the J2000 epoch, nor classical 12-part zodiac. The ecliptic passes less than 0.25° from one of its corners. Thus the moon and planets will enter Cetus (occulting any stars as a foreground object) in 50% of their successive orbits briefly and the southern part of the sun appears in Cetus for about one day each year. Many asteroids in belts have longer phases occulting the north-western part of Cetus, those with a slightly greater inclination to the ecliptic than the moon and planets. As seen from Mars, the ecliptic (apparent plane of the sun and also the average plane of the planets which is almost the same) passes into it. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Near Infrared Survey Of The Southern Sky
The Deep Near Infrared Survey of the Southern Sky (DENIS) was a deep astronomical survey of the southern sky in the near-infrared and optical wavelengths, using an ESO 1-meter telescope at the La Silla Observatory. It operated from 1996 to 2001. See also * DENIS-P J1058.7-1548 * DENIS-P J1228.2-1547 * DENIS-P J020529.0-115925 * DENIS-P J082303.1-491201 b * DENIS-P J101807.5-285931 * DENIS J024011.0-014628,6dFGS gJ024011.1-014628 * Edinburgh-Cape Blue Object Survey The Edinburgh-Cape Blue Object Survey (or EC in astronomical notation)C. Aerts, J. Christensen-Dalsgaard, D. W. Kurtz, ''Asteroseismology'' (2010), p. 105. is a major astronomical survey to discover blue stellar objects brighter than B~18 in the so ... References External links DENIS—Deep Near Infrared Survey of the Southern SkyESO 1-metre telescope Astronomical catalogues Astronomical surveys {{astronomical-catalogue-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Galaxy 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] |
Low-surface-brightness Galaxy
A low-surface-brightness galaxy, or LSB galaxy, is a diffuse galaxy with a surface brightness that, when viewed from Earth, is at least one magnitude lower than the ambient night sky. Most LSBs are dwarf galaxies, and most of their baryonic matter is in the form of neutral gaseous hydrogen, rather than stars. They appear to have over 95% of their mass as non-baryonic dark matter. There appears to be little supernova (SN) activity in these galaxies, although LSB galaxy IC 217 hosted 2014cl. Rotation curve measurements indicate an extremely high mass-to-light ratio, meaning that stars and luminous gas contribute only very little to the overall mass balance of an LSB. The centers of LSBs show no large overdensities in stars, unlike e.g. the bulges of normal spiral galaxies. Therefore, they seem to be dark-matter-dominated even in their centers, which makes them excellent laboratories for the study of dark matter. In comparison to the high-surface-brightness galaxies, LSBs are ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Galaxy
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Alt URL pp. 124–151) and, as such, form part of the . Most spiral galaxies consist of a flat, rotating containing s, gas and dust, and a central concentration of stars known as the |
Light-year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry; it is the distance at which one astronomical unit subtends an angle of one second of arc. Defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. The 48 traditional Western constellations are Greek. They are given in Aratus' work ''Phenomena'' and Ptolemy's ''Almagest'', though their origin probably predates these works by several centuries. Constellation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malin 1
__NOTOC__ Malin 1 is a giant low surface brightness (LSB) spiral galaxy. It is located away in the constellation Coma Berenices, near the North Galactic Pole. , it is the largest known spiral galaxy, with an approximate diameter of , thus over six times the diameter of our Milky Way. It was discovered by astronomer David Malin in 1986 and is the first LSB galaxy verified to exist. Its high surface brightness central spiral is across, with a bulge of . The central spiral is a SB0a type barred-spiral. Malin 1 is peculiar in several ways: its diameter alone would make it the largest barred spiral galaxy ever to have been observed. Malin 1 was found later to be interacting with two other galaxies, Malin 1B and SDSS J123708.91+142253.2. Malin 1B is located away from the high surface brightness central spiral of Malin 1, which may be responsible for the formation of the galaxy's central bar. Meanwhile, SDSS J123708.91+142253.2 is located within the huge, faint halo of Malin 1 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Surface Brightness Galaxy
A low-surface-brightness galaxy, or LSB galaxy, is a diffuse galaxy with a surface brightness that, when viewed from Earth, is at least one magnitude lower than the ambient night sky. Most LSBs are dwarf galaxies, and most of their baryonic matter is in the form of neutral gaseous hydrogen, rather than stars. They appear to have over 95% of their mass as non-baryonic dark matter. There appears to be little supernova (SN) activity in these galaxies, although LSB galaxy IC 217 hosted 2014cl. Rotation curve measurements indicate an extremely high mass-to-light ratio, meaning that stars and luminous gas contribute only very little to the overall mass balance of an LSB. The centers of LSBs show no large overdensities in stars, unlike e.g. the bulges of normal spiral galaxies. Therefore, they seem to be dark-matter-dominated even in their centers, which makes them excellent laboratories for the study of dark matter. In comparison to the high-surface-brightness galaxies, LSBs are ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
