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NGC 4643
NGC 4643 is a lenticular galaxy located in the constellation Virgo. It is a member of the NGC 4753 Group of galaxies, which is a member of the Virgo II Groups The Virgo II Groups, also known as the Virgo II Cloud, Virgo Southern Extension, or the Virgo S Cloud, are a series of at least 100 galactic clusters and individual galaxies stretching approximately off the southern edge of the Virgo Supercluster ..., a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. References External links * Virgo (constellation) 4643 Barred lenticular galaxies 042797 {{lenticular-galaxy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Energy Spectroscopic Instrument
The Dark Energy Spectroscopic Instrument (DESI) is a scientific research instrument for conducting spectrographic astronomical surveys of distant galaxies. Its main components are a focal plane containing 5,000 fiber-positioning robots, and a bank of spectrographs which are fed by the fibers. The new instrument will enable an experiment to probe the expansion history of the universe and the mysterious physics of dark energy. The instrument is operated by the Lawrence Berkeley National Laboratory under funding from the US Department of Energy's Office of Science. Construction of the new instrument, now completed, was principally funded by the US Department of Energy's Office of Science, and by other numerous sources including the US National Science Foundation, the UK Science and Technology Facilities Council, France's Alternative Energies and Atomic Energy Commission, Mexico's National Council of Science and Technology, Spain's Ministry of Science and Innovation, by the Gordon ... [...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] |
Virgo (constellation)
Virgo is one of the constellations of the zodiac. Its name is Latin for maiden, and its old astronomical symbol is (♍︎). Lying between Leo (constellation), Leo to the west and Libra (constellation), Libra to the east, it is the second-largest constellation in the sky (after Hydra (constellation), Hydra) and the largest constellation in the zodiac. The ecliptic intersects the celestial equator within this constellation and Pisces (constellation), Pisces. Underlying these technical two definitions, the sun passes directly overhead of the equator, within this constellation, at the September equinox. Virgo can be easily found through its brightest star, Spica. Location Virgo is prominent in the spring sky in the Northern Hemisphere, visible all night in March and April. As the largest zodiac constellation, the Sun takes 44 days to pass through it, longer than any other. From 1990 and until 2062, this will take place from September 16 to October 30. It is located in the third ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgo Cluster
The Virgo Cluster is a large cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the constellation Virgo. Comprising approximately 1,300 (and possibly up to 2,000) member galaxies, the cluster forms the heart of the larger Virgo Supercluster, of which the Local Group (containing our Milky Way galaxy) is a member. The Local Group actually experiences the mass of the Virgo Supercluster as the Virgocentric flow. It is estimated that the Virgo Cluster's mass is 1.2 out to 8 degrees of the cluster's center or a radius of about 2.2 Mpc. Many of the brighter galaxies in this cluster, including the giant elliptical galaxy Messier 87, were discovered in the late 1770s and early 1780s and subsequently included in Charles Messier's catalogue of non-cometary fuzzy objects. Described by Messier as nebulae without stars, their true nature was not recognized until the 1920s. The cluster subtends a maximum arc of approximately 8 degrees centered in the constellation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lenticular Galaxy
A lenticular galaxy (denoted S0) is a type of galaxy intermediate between an elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. It contains a large-scale disc but does not have large-scale spiral arms. Lenticular galaxies are disc galaxies that have used up or lost most of their interstellar matter and therefore have very little ongoing star formation. They may, however, retain significant dust in their disks. As a result, they consist mainly of aging stars (like elliptical galaxies). Despite the morphological differences, lenticular and elliptical galaxies share common properties like spectral features and scaling relations. Both can be considered early-type galaxies that are passively evolving, at least in the local part of the Universe. Connecting the E galaxies with the S0 galaxies are the ES galaxies with intermediate-scale discs. Morphology and structure Classification Lenticular galaxies are unique in that they have a visibl ... [...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] |
NGC 4753 Group
The Virgo II Groups, also known as the Virgo II Cloud, Virgo Southern Extension, or the Virgo S Cloud, are a series of at least 100 galactic clusters and individual galaxies stretching approximately off the southern edge of the Virgo Supercluster. It is located approximately to from the Solar System, at a right ascension of to . These clusters include: *M61 Group: ** IC 3474 ** M61 (NGC 4303) ** NGC 4255 ** NGC 4420 **NGC 4496A ** NGC 4517A ** NGC 4527 ** NGC 4533 **NGC 4536 ** NGC 4581 ** NGC 4599 **NGC 4632 **PGC 40951 ** UGC 7387 ** UGC 7522 **UGC 7612 **UGC 7780 *NGC 4030 Group: **NGC 4030 **UGC 6970 **UGC 7000 *NGC 4179 Group: **NGC 4116 **NGC 4123 **NGC 4179 ** UGC 7035 *NGC 4697 Group: ** IC 3908 ** MCG-1-33-1 ** MCG-1-33-3 ** MCG-1-33-11 ** MCG-1-33-33 ** MCG-1-33-59 ** MCG-1-33-61 ** MCG-1-33-82 **NGC 4697 **NGC 4731 ** NGC 4775 ** NGC 4941 ** NGC 4948 ** NGC 4948A **NGC 4951 ** NGC 4958 **UGCA 310 * NGC 4699 Group: ** MCG-2-33-15 ** MCG-2-33-47 ** MCG-1-33-60 ** MCG-2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgo II Groups
The Virgo II Groups, also known as the Virgo II Cloud, Virgo Southern Extension, or the Virgo S Cloud, are a series of at least 100 galactic clusters and individual galaxies stretching approximately off the southern edge of the Virgo Supercluster. It is located approximately to from the Solar System, at a right ascension of to . These clusters include: * M61 Group: ** IC 3474 ** M61 (NGC 4303) ** NGC 4255 ** NGC 4420 ** NGC 4496A ** NGC 4517A ** NGC 4527 ** NGC 4533 ** NGC 4536 ** NGC 4581 ** NGC 4599 ** NGC 4632 ** PGC 40951 ** UGC 7387 ** UGC 7522 **UGC 7612 ** UGC 7780 * NGC 4030 Group: **NGC 4030 ** UGC 6970 ** UGC 7000 * NGC 4179 Group: ** NGC 4116 ** NGC 4123 ** NGC 4179 ** UGC 7035 * NGC 4697 Group: ** IC 3908 ** MCG-1-33-1 ** MCG-1-33-3 ** MCG-1-33-11 ** MCG-1-33-33 ** MCG-1-33-59 ** MCG-1-33-61 ** MCG-1-33-82 **NGC 4697 **NGC 4731 ** NGC 4775 ** NGC 4941 ** NGC 4948 ** NGC 4948A ** NGC 4951 ** NGC 4958 ** UGCA 310 * NGC 4699 Group: ** MCG-2-33-15 ** MCG-2-33-47 ** MCG- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Cluster
A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-largest known gravitationally bound structures in the universe after galaxy filaments and were believed to be the largest known structures in the universe until the 1980s, when superclusters were discovered. One of the key features of clusters is the intracluster medium (ICM). The ICM consists of heated gas between the galaxies and has a peak temperature between 2–15 keV that is dependent on the total mass of the cluster. Galaxy clusters should not be confused with ''galactic clusters'' (also known as open clusters), which are star clusters ''within'' galaxies, or with globular clusters, which typically orbit galaxies. Small aggregates of galaxies are referred to as galaxy groups rather than clusters of galaxies. The galaxy groups and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgo Supercluster
The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs (110 million light-years). The Virgo SC is one of about 10 million superclusters in the observable universe and is in the Pisces–Cetus Supercluster Complex, a galaxy filament. A 2014 study indicates that the Virgo Supercluster is only a lobe of an even greater supercluster, Laniakea, a larger, competing referent of the term Local Supercluster centered on the Great Attractor. Background Beginning with the first large sample of nebulae published by William and John Herschel in 1863, it was known that there is a marked excess of nebular fields in the constellation Virgo (near the north galactic pole). In the 1950s, French–American astronomer Gérard de Vau ... [...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] |
Barred Lenticular Galaxies
A lenticular galaxy (denoted S0) is a type of galaxy intermediate between an elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. It contains a large-scale disc but does not have large-scale spiral arms. Lenticular galaxies are disc galaxies that have used up or lost most of their interstellar matter and therefore have very little ongoing star formation. They may, however, retain significant dust in their disks. As a result, they consist mainly of aging stars (like elliptical galaxies). Despite the morphological differences, lenticular and elliptical galaxies share common properties like spectral features and scaling relations. Both can be considered early-type galaxies that are passively evolving, at least in the local part of the Universe. Connecting the E galaxies with the S0 galaxies are the ES galaxies with intermediate-scale discs. Morphology and structure Classification Lenticular galaxies are unique in that they have a visibl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
