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3C 454.3
3C 454.3 is a blazar (a type of quasar with a jet oriented toward Earth) located away from the galactic plane. It is one of the brightest gamma ray sources in the sky, and is one of the most luminous astronomical object ever observed, with a maximum absolute magnitude of -31.4. It has the brightest blazar gamma ray flare recorded, twice as bright as the Vela Pulsar in the Milky Way galaxy. It also flares at radio and visible wavelengths – in red light, the blazar brightened by more than 2.5 times to magnitude 13.7 – and it is very bright at high radio frequencies. It appears in Pegasus, near Alpha Pegasi (Markab). It has been known to occasionally outburst, brightening to a peak apparent magnitude of 13.4 in June 2014. History In July and August 2007, the gamma-ray blazar 3C 454.3 flared to near-historic levels, only two years after its record-breaking 2005 optical flare. Luckily, Spitzer Space Telescope and Chandra X-ray Observatory were already scheduled for simultan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Third Cambridge Catalogue Of Radio Sources
The Third Cambridge Catalogue of Radio Sources (3C) is an astronomical catalogue of celestial radio sources detected originally at 159 MHz, and subsequently at 178 MHz. History 3C The catalogue was published in 1959 by members of the Cavendish Astrophysics Group, Radio Astronomy Group of the University of Cambridge. Entries in the catalogue are identified by the prefix "3C" followed by the entry number, with a space - for example, 3C 273. The catalogue was produced using the Cambridge Interferometer on the west side of Cambridge. The interferometer had previously been used for the Second Cambridge Catalogue of Radio Sources (2C) survey, published in 1955. 3CR The catalogue was subsequently revised by Bennett in 1962 using observations at 178 MHz, and for many years '3CR' was considered as the definitive listing of the brighter radio sources in the Northern Hemisphere. The revision resulted in a number of sources being deleted from the catalogue (as being below the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vela Pulsar
The Vela Pulsar (PSR J0835-4510 or PSR B0833-45) is a radio, optical, X-ray- and gamma-emitting pulsar associated with the Vela Supernova Remnant in the constellation of Vela. Its parent Type II supernova exploded approximately 11,000–12,300 years ago (and was about 800 light-years away). Characteristics Vela is the brightest pulsar (at radio frequencies) in the sky and spins 11.195 times per second (i.e. a period of 89.33 milliseconds—the shortest known at the time of its discovery) and the remnant from the supernova explosion is estimated to be travelling outwards at . It has the third-brightest optical component of all known pulsars (V = 23.6 mag) which pulses twice for every single radio pulse. The Vela pulsar is the brightest persistent object in the high-energy gamma-ray sky. Glitches Glitches are sudden spin-ups in the rotation of pulsars. Vela is the best known of all the glitching pulsars, with glitches occurring on average every three years. Glitches ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3C Objects
3C may refer to: In astronomy: * 3C, the ''Third Cambridge Catalogue of Radio Sources'', an astronomical reference series In business: * Long March 3C, a 2008 Chinese orbital rocket * 3C Records, a record label * 3C (radio), a defunct digital radio station * Team 3C Casalinghi Jet Androni Giocattoli, a defunct Italian professional cycling team * 3C, the IATA code for defunct American airline RegionsAir * Three-cent piece * 3C (trade association) is an American trade association. In computing: * Three Cs (Compulsory, Capacity, and Conflict), three categories of CPU cache misses * 3C, or Computer Control Company, Inc., a pioneering minicomputer company (1953–1966) * Agile model: 3C (Card, Conversation, Confirmation) * 3C, an abbreviation often used in Taiwan for "computer, communication, and consumer electronics" In genetics: * Alpha-tubulin 3C, a human gene * 3C, or Chromosome conformation capture, a technique used in molecular biology Substituted amphetamines ( 2C family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OVV Quasars
OVV can refer to: * OVV quasar * Orient Air (ICAO airline code OVV), Syrian airline; see List of airline codes (O) * Ovintiv (stock ticker: OVV), hydrocarbon exploration company * Dutch Safety Board ( nl, link=no, Onderzoeksraad Voor Veiligheid, OVV) * ( nl, link=no, Overlegcentrum van Vlaamse Verenigingen, OVV) * ( nl, link=no, Oostvoornse Voetbalvereniging, OVV), a soccer club * (german: link=no, Österreichischer Volleyballverband, ÖVV) * Venezuelan Violence Observatory ( es, link=no, Observatorio Venezolano de Violencia, OVV), see Crime in Venezuela * Order of Vittorio Veneto (O.V.V.), see List of post-nominal letters (Italy) See also * O2V (other) * OV2 (other) * OW (other) * OOV (other) OOV may refer to: * Oov, a dialect of the Mutu language * Our Own Voice Literary Journal: Beyond Homeland (OOV), a Philippine literary journal * out of vision (OOV), see Glossary of broadcasting terms * Out of vocabulary (OOV), words not found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Galactic Nucleus
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars. Such excess non-stellar emission has been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an "active galaxy". The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy. Active galactic nuclei are the most luminous persistent sources of electromagnetic radiation in the universe, and as such can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on models of the cosmos. The observed characteristics of an AGN depend on several properties such as the mass of the central black hole, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermi Gamma-ray Space Telescope
The Fermi Gamma-ray Space Telescope (FGST, also FGRST), formerly called the Gamma-ray Large Area Space Telescope (GLAST), is a space observatory being used to perform gamma-ray astronomy observations from low Earth orbit. Its main instrument is the Large Area Telescope (LAT), with which astronomers mostly intend to perform an all-sky survey studying astrophysical and cosmological phenomena such as active galactic nuclei An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not prod ..., pulsars, other high-energy sources and dark matter. Another instrument aboard Fermi, the Gamma-ray Burst Monitor (GBM; formerly GLAST Burst Monitor), is being used to study gamma-ray bursts and solar flares. Fermi, named for high-energy physics pioneer Enrico Fermi, was launched on 11 June 2008 at 16:05 UTC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, following IRAS (1983) and ISO (1995–1998). It was the first spacecraft to use an Earth-trailing orbit, later used by the Kepler planet-finder. The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium supply was exhausted. This occurred on 15 May 2009. Without liquid helium to cool the telescope to the very low temperatures needed to operate, most of the instruments were no longer usable. However, the two shortest-wavelength modules of the IRAC camera continued to operate with the same sensitivity as before the helium was exhausted, and continued to be used into early 2020 in the Spitzer Warm Mission. During the warm mission, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Association Of Variable Star Observers
The American Association of Variable Star Observers (AAVSO) is an international nonprofit organization, founded in 1911, focused on coordinating, analyzing, publishing, and archiving variable star observations made largely by amateur astronomers. The AAVSO creates records that establish light curves depicting the variation in brightness of a star over time, and makes them available to professional astronomers, researchers, and educators. Since professional astronomers do not have the time or the resources to monitor every variable star, astronomy is one of the few sciences where amateurs can make genuine contributions to scientific research. During 2011, the 100th year of the AAVSO's existence, the 20-millionth variable star observation was received into the database. The AAVSO International Database (AID) stores over 35 million observations as of 2019. The organization receives nearly 1,000,000 observations annually from around 2,000 professional and amateur observers and is quot ... [...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] |
Alpha Pegasi
Alpha Pegasi (α Pegasi, abbreviated Alpha Peg, α Peg), formally named Markab , is the third-brightest star in the constellation of Pegasus and one of the four stars in the asterism known as the Great Square of Pegasus. Properties Alpha Pegasi has a stellar classification of A0 IV, indicating that it is an A-type subgiant star that has exhausted the hydrogen at its core and has evolved beyond the main sequence. Its spectrum has also been classified as B9V and B9.5III. It is rotating rapidly, with a projected rotational velocity of 130 km/s giving a lower bound on the azimuthal velocity along the star's equator. The effective temperature of the photosphere is about 10,000 K and the star has expanded to nearly five times the radius of the Sun, emitting 165 times as much energy as the sun. Nomenclature ''α Pegasi'' ( Latinised to ''Alpha Pegasi'') is the star's Bayer designation. It bore the traditional name ''Markab'' (or ''Marchab''), which derived fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absolute Magnitude
Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly , without Extinction (astronomy), extinction (or dimming) of its light due to absorption by Interstellar medium, interstellar matter and cosmic dust. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared among each other on a magnitude scale. As with all astronomical magnitude (astronomy), magnitudes, the absolute magnitude can be specified for different wavelength ranges corresponding to specified Filter (optics), filter bands or passbands; for stars a commonly quoted absolute magnitude is the absolute visual magnitude, which uses the visual (V) band of the spectrum (in the UBV phot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
