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Lists Of Galaxies
This is a list of lists of galaxies. Lists of galaxies * List of galaxies, general list of galaxies ; Galaxies by type * List of spiral galaxies * List of ring galaxies * List of polar-ring galaxies * List of quasars ; Galaxies by association * List of largest galaxies * List of nearest galaxies * Satellite galaxies of the Milky Way ; Other characteristics * List of galaxies named after people * List of galaxies with richest globular cluster systems Lists of galaxy agglomerations * List of galaxy groups and clusters * List of galaxy superclusters * List of filaments of galaxies See also * Lists of astronomical objects * List of black holes * Lists of clusters * List of voids * List of the most distant astronomical objects This article documents the most distant astronomical objects discovered and verified so far, and the time periods in which they were so classified. For comparisons with the light travel distance of the astronomical objects listed below, the age of ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Galaxy Groups And Clusters
This article lists some galaxy groups and galaxy clusters. Defining the limits of galaxy clusters is imprecise as many clusters are still forming. In particular, clusters close to the Milky Way tend to be classified as galaxy clusters even when they are much smaller than more distant clusters. Clusters exhibiting strong evidence of dark matter Some clusters exhibiting strong evidence of dark matter. Named groups and clusters This is a list of galaxy groups and clusters that are well known by something other than an entry in a catalog or list, or a set of coordinates, or a systematic designation. Clusters Groups The major nearby groups and clusters are generally named after the constellation they lie in. Many groups are named after the leading galaxy in the group. This represents an ad hoc systematic naming system. Groups and clusters visible to the unaided eye The Local Group contains the largest number of visible galaxies with the naked eye. However, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of The Most Distant Astronomical Objects
This article documents the most distant astronomical objects discovered and verified so far, and the time periods in which they were so classified. For comparisons with the light travel distance of the astronomical objects listed below, the age of the universe since the Big Bang is currently estimated as 13.787±0.020 Gyr. Distances to remote objects, other than those in nearby galaxies, are nearly always inferred by measuring the cosmological redshift of their light. By their nature, very distant objects tend to be very faint, and these distance determinations are difficult and subject to errors. An important distinction is whether the distance is determined via spectroscopy or using a photometric redshift technique. The former is generally both more precise and also more reliable, in the sense that photometric redshifts are more prone to being wrong due to confusion with lower redshift sources that may have unusual spectra. For that reason, a spectroscopic redshift is conventio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Voids
This is a list of voids in astronomy. Voids are particularly galaxy-poor regions of space between filaments, making up the large-scale structure of the universe. Some voids are known as ''supervoids''. In the tables, ''z'' is the cosmological redshift, ''c'' the speed of light, and ''h'' the dimensionless Hubble parameter, which has a value of approximately 0.7 (the Hubble constant ''H''0 = ''h'' × 100 km s−1 Mpc−1). Mpc stands for megaparsec. The co-ordinates (right ascension and declination) and distance given refer to the approximate center of the region. Voids and supervoids Largest voids Named voids SIMBAD"list of objects in '*void' wildcard search"(accessed 15 September 2009)SIMBAD"list of objects of type 'vid'"(accessed 15 September 2009) Voids designated by their constellation Other voids Voids by search or survey Tully list In 1985, Tully determined a local dominant supercluster plane, and found the Pisces–Cetus Superclust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lists Of Clusters
The following are lists of clusters: * List of galaxy groups and clusters * List of open clusters * List of globular clusters This is a list of globular clusters. The apparent magnitude does not include an extinction correction. Milky Way These are globular clusters within the halo of the Milky Way galaxy. The diameter is in minutes of arc as seen from Earth. For re ... See also * List of superclusters {{DEFAULTSORT:Clusters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Black Holes
This list of black holes (and stars considered probable candidates) is organized by mass (including black holes of undetermined mass); some items in this list are galaxies or star clusters that are believed to be organized around a black hole. Messier and New General Catalogue designations are given where possible. Supermassive black holes and candidates * 1ES 2344+514 * Ton 618 (this quasar has possibly the biggest black hole ever found, estimated at 66 billion solar masses) * 3C 371 * 4C +37.11 (this radio galaxy is believed to have binary supermassive black holes) * AP Lib * S5 0014+81 (said to be a compact hyperluminous quasar, estimated at 40 billion solar masses) 17:53:24 GMT. * APM 08279+5255 (contains one of the largest black holes, estimated at 10-23 billion solar masses; previous candidate for largest) * Arp 220 * Centaurus A * Fornax A * HE0450-2958 * IC 1459 * Messier 31 (or the Andromeda Galaxy) * Messier 32 * Messier 51 (or the Whirlpool Galaxy) * Messier 60 * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
