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M94 Group
The M94 Group (Canes I Group or Canes Venatici I Group) is a loose, extended group of galaxies located about 13 million light-years away in the constellations Canes Venatici and Coma Berenices. The group is one of many groups that lies within the Virgo Supercluster (i.e. the Local Supercluster) and one of the closest groups to the Local Group. Although the galaxies in this cluster appear to be from a single large cloud-like structure, many of the galaxies within the group are only weakly gravitationally bound, and some have not yet formed stable orbits around the center of this group. Instead, most of the galaxies in this group appear to be moving with the expansion of the universe. Members The table below lists galaxies that have been consistently identified as group members in the Nearby Galaxies Catalog, the Lyons Groups of Galaxies (LGG) Catalog, and the three group lists created from the Nearby Optical Galaxy sample of Giuricin et al. Additionally, NGC 4105 and DDO 16 ... [...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] |
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing house specializing in monographs and scholarly journals. Most are nonprofit organizations and an integral component of a large research university. They publish work that has been reviewed by schola ... in the world. It is also the King's Printer. Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. It became part of Cambridge University Press & Assessment, following a merger with Cambridge Assessment in 2021. With a global sales presence, publishing hubs, and offices in more than 40 Country, countries, it publishes over 50,000 titles by authors from over 100 countries. Its publishing includes more than 380 academic journals, monographs, reference works, school and uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4244
NGC 4244, also known as Caldwell 26, is an edge-on loose spiral galaxy in the constellation Canes Venatici, and is part of the M94 Group or Canes Venatici I Group, a galaxy group relatively close to the Local Group containing the Milky Way. In the sky, it is located near the yellow naked-eye star, Beta Canum Venaticorum, but also near the barred spiral galaxy NGC 4151 and irregular galaxy NGC 4214. With an apparent V-band magnitude of 10.18, NGC 4244 lies approximately 4.3 megaparsecs (14 million light years) away. A nuclear star cluster A nuclear star cluster (NSC) or compact stellar nucleus (sometimes called young stellar nucleus) is a star cluster with high density and high luminosity near the center of mass of most galaxies. NSCs are the central massive objects of fainter ... and halo is located near the centre of this galaxy. See also * IC 5052 - a similar edge-on galaxy Notes References * * External links * * {{DEFAULTSORT:NGC 4244 Unbarred spir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4214
NGC 4214 is a dwarf barred irregular galaxy located around 10 million light-years away in the constellation Canes Venatici. NGC 4214 is a member of the M94 Group. Characteristics NGC 4214 is both larger and brighter than the Small Magellanic Cloud as well as a starburst galaxy, with the largest star-forming regions (''NGC 4214-I'' and ''NGC 4214-II'') in the galaxy's center. Of the two, ''NGC 4214-I'' contains a super star cluster rich in Wolf-Rayet stars and ''NGC 4214-II'' is younger (age less than 3 million years), including a number of star clusters and stellar associations. NGC 4214 also has two older super star clusters, both with an age of 200 million years and respective masses of 2.6*10.5 and 1.5*106 solar masses. Two satellites are known to exist around the vicinity of NGC 4214. One is DDO 113, which has an absolute V-band magnitude of −12.2. It stopped star formation around 1 billion years ago. Another, more recently discovered object is MADCASH-2, offic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4190
NGC commonly refers to: * New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy NGC may also refer to: Companies * NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998 * National Gas Company of Trinidad and Tobago, 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, aerospace and defense conglomerate formed from the merger of Northrop Corporation and Grumman Corporation in 1994 * Numismatic Guaranty Corporation, coin certification company in the United States Other uses * National Gallery of Canada, art gallery founded in 1880 in Ottawa, Canada * National Geographic, documentary and reality television channel established in the United States in 2001 formerly called National Geographic Channel * Native Girls Code, US non-profit organisat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4144
NGC 4144 is a barred spiral galaxy in the constellation Ursa Major. It was discovered by William Herschel on April 10, 1788. Gallery NGC4144 - SDSS DR14.jpg, NGC 4144 by the Sloan Digital Sky Survey NGC 4144 GALEX WikiSky.jpg, NGC 4144 by GALEX NGC 4144 HST 9765 R814GB606.png, Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ... References External links * Ursa Major Astronomical objects discovered in 1788 Barred spiral galaxies Discoveries by William Herschel 4144 038688 {{Spiral-galaxy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer. The word ''magnitude'' in astronomy, unless stated otherwise, usually refers to a celestial object's apparent magnitude. The magnitude scale dates back to the ancient Roman astronomer Claudius Ptolemy, whose star catalog listed stars from 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined in a way to closely match this historical system. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. A difference of 1.0 in magnitude corresponds to a brightness ratio of \sqrt /math>, or about 2.512. For example, a star of magnitude 2.0 is 2.512 times as bright as a star of magnitude 3.0, 6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units ( SI) is more precise:The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. Because the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. Uses Analog clocks and watches often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilometer
The kilometre ( SI symbol: km; or ), spelt kilometer in American English, is a unit of length in the International System of Units (SI), equal to one thousand metres (kilo- being the SI prefix for ). It is now the measurement unit used for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the United Kingdom where the statute mile is the unit used. The abbreviations k or K (pronounced ) are commonly used to represent kilometre, but are not recommended by the BIPM. A slang term for the kilometre in the US, UK, and Canadian militaries is ''klick''. Pronunciation There are two common pronunciations for the word. # # The first pronunciation follows a pattern in English whereby metric units are pronounced with the stress on the first syllable (as in kilogram, kilojoule and kilohertz) and the pronunciation of the actual base unit does not change irrespective of the prefix (as in centimetre, millimetre, na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redshift
In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in frequency and energy, is known as a negative redshift, or blueshift. The terms derive from the colours red and blue which form the extremes of the visible light spectrum. In astronomy and cosmology, the three main causes of electromagnetic redshift are # The radiation travels between objects which are moving apart (" relativistic" redshift, an example of the relativistic Doppler effect) #The radiation travels towards an object in a weaker gravitational potential, i.e. towards an object in less strongly curved (flatter) spacetime (gravitational redshift) #The radiation travels through expanding space (cosmological redshift). The observation that all sufficiently distant light sources show redshift corresponding to their distance from Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
