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Microquasars
A microquasar, the smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its companion star. The matter being pulled from the companion star forms an accretion disk around the black hole. This accretion disk may become so hot, due to friction, that it begins to emit X-rays. The disk also projects narrow streams or " jets" of subatomic particles at near-light speed, generating a strong radio wave emission. Overview In 1979, SS 433 became the first microquasar to be discovered. It was thought to be the most exotic case until similar objects such as GRS 1915+105 were discovered in 1994. In some cases, blobs or "knots" of brighter plasma within the jets appear to be traveling faster than the speed of light, an optical illusion called superluminal motion which is caused by sub-light-speed particles being projected at a small angle relative to the observer. The 1996 Bruno Rossi Prize of the American Astronomical Society was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Binaries
X-ray binaries are a class of binary stars that are luminous in X-rays. The X-rays are produced by matter falling from one component, called the ''donor'' (usually a relatively normal star), to the other component, called the ''accretor'', which is very compact: a neutron star or black hole. The infalling matter releases gravitational potential energy, up to several tenths of its rest mass, as X-rays. (Hydrogen fusion releases only about 0.7 percent of rest mass.) The lifetime and the mass-transfer rate in an X-ray binary depends on the evolutionary status of the donor star, the mass ratio between the stellar components, and their orbital separation. An estimated 1041 positrons escape per second from a typical low-mass X-ray binary. Classification X-ray binaries are further subdivided into several (sometimes overlapping) subclasses, that perhaps reflect the underlying physics better. Note that the classification by mass (high, intermediate, low) refers to the optically vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microquasars
A microquasar, the smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its companion star. The matter being pulled from the companion star forms an accretion disk around the black hole. This accretion disk may become so hot, due to friction, that it begins to emit X-rays. The disk also projects narrow streams or " jets" of subatomic particles at near-light speed, generating a strong radio wave emission. Overview In 1979, SS 433 became the first microquasar to be discovered. It was thought to be the most exotic case until similar objects such as GRS 1915+105 were discovered in 1994. In some cases, blobs or "knots" of brighter plasma within the jets appear to be traveling faster than the speed of light, an optical illusion called superluminal motion which is caused by sub-light-speed particles being projected at a small angle relative to the observer. The 1996 Bruno Rossi Prize of the American Astronomical Society was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Microquasars ...
This is a list of all known microquasars: 1 * 1E 1740,7-2942 4 * 4U1630-47 C *Cygnus X-1 * Cygnus X-3 (V1521) *CI Cam G *GRS 1915+105 *GRO J1655-40 * GX339-4 K * KS1731-260 L *LS I +61 303 * LS 5039 S *Scorpius X-1 *SS 433 V * V4641 Sgr *V691 CrA X * XMMU J004243.6+412519 * XTE J1118+480 * XTE J1550-564 See also * List of quasars References {{black holes * microquasars A microquasar, the smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its companion star. The matter being pulled from the companion star forms an accretion disk around the black hole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SS 433
SS 433 is one of the most exotic star systems observed. It is located in the Milky Way galaxy, and is an eclipsing X-ray binary system, with the primary being a stellar-mass black hole. The spectrum of the secondary companion star suggests that it is a late A-type star. SS 433 is the first discovered microquasar. It is at the centre of the supernova remnant W50. SS 433's designation comes from the initials of two astronomers at Case Western Reserve University: Nicholas Sanduleak and Charles Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines.SS 433 David Darling, entry in ''The Internet Encyclopedia of Science'', accessed on line September 14, 2007. Its emission lines were studied by |
Ss433 Art Big
SS 433 is one of the most exotic star systems observed. It is located in the Milky Way galaxy, and is an eclipsing X-ray binary system, with the primary being a stellar-mass black hole. The spectrum of the secondary companion star suggests that it is a late A-type star. SS 433 is the first discovered microquasar. It is at the centre of the supernova remnant W50. SS 433's designation comes from the initials of two astronomers at Case Western Reserve University: Nicholas Sanduleak and Charles Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines.SS 433 David Darling, entry in ''The Internet Encyclopedia of Science'', accessed on line September 14, 2007. Its emission lines were studied by |
Great Annihilator
1E1740.7-2942, or the Great Annihilator, is a Milky Way microquasar, located near the Galactic Center on the sky. It likely consists of a black hole and a companion star. It is one of the brightest X-ray sources in the region around the Galactic Center. The object was first detected in soft X-rays by the Einstein Observatory, and later detected in hard X-rays by the Soviet Granat space observatory. Followup observations by the SIGMA detector on board Granat showed that the object was a variable emitter of massive amounts of photon pairs at 511 keV, which usually indicates the annihilation of an electron-positron pair. This led to the nickname, "Great Annihilator." Early observations also showed a spectrum similar to that of the Cygnus X-l, a black hole with a stellar companion, which suggested that Great Annihilator was also a stellar mass black hole. The object also has a radio source counterpart that emits jets approximately 1.5 pc (5 ly) long. These jets are probably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Star
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough they can gravitationally distort their mutual outer stellar atmospheres. In some cases, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GRS 1915+105
GRS may refer to: Education * Geneva Reformed Seminary, in Greenville, South Carolina * Gifted Rating Scales, an educational assessment test * Great River Charter Montessori School, in St. Paul, Minnesota Science * Gamma-ray spectrometer * Gamma Ray Spectrometer (''2001 Mars Odyssey''), an instrument on ''2001 Mars Odyssey'' * Genetic risk score * Great Red Spot, a feature on Jupiter Other uses * General Railway Signal, a former American railway signaling company * Gender-affirming surgery, also known as gender reassignment surgery * '' The Gerry Ryan Show'', an Irish radio show * Global Resource Serialization, part of the IBM z/OS operating system * Government Rubber-Styrene (GR-S) produced by the United States Synthetic Rubber Program during World War II * Grand Rapids Symphony, in Michigan * Grassroot Soccer, an international health organization * Graves Registration Service, now Mortuary Affairs, a service of the United States Army * Gresi language * Grosseto Air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accretion Disk
An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is typically a star. Friction, uneven irradiance, magnetohydrodynamic effects, and other forces induce instabilities causing orbiting material in the disk to spiral inward towards the central body. Gravitational and frictional forces compress and raise the temperature of the material, causing the emission of electromagnetic radiation. The frequency range of that radiation depends on the central object's mass. Accretion disks of young stars and protostars radiate in the infrared; those around neutron stars and black holes in the X-ray part of the spectrum. The study of oscillation modes in accretion disks is referred to as diskoseismology. Manifestations Accretion disks are a ubiquitous phenomenon in astrophysics; active galactic nuclei, protoplanetary disks, and gamma ray bursts all involve accretion disks. These disks ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Black Hole
A stellar black hole (or stellar-mass black hole) is a black hole formed by the gravitational collapse of a star. They have masses ranging from about 5 to several tens of solar masses. The process is observed as a hypernova explosion or as a gamma ray burst. These black holes are also referred to as collapsars. Properties By the no-hair theorem, a black hole can only have three fundamental properties: mass, electric charge, and angular momentum. The angular momentum of a stellar black hole is due to the conservation of angular momentum of the star or objects that produced it. The gravitational collapse of a star is a natural process that can produce a black hole. It is inevitable at the end of the life of a large star when all stellar energy sources are exhausted. If the mass of the collapsing part of the star is below the Tolman–Oppenheimer–Volkoff (TOV) limit for neutron-degenerate matter, the end product is a compact star – either a white dwarf (for masses below the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 au subtends an angle of one arcsecond ( of a degree). This corresponds to astronomical units, i.e. 1\, \mathrm = 1/\tan \left( \ \mathrm \right)\, \mathrm. The nearest star, Proxima Centauri, is about from the Sun. Most stars visible to the naked eye are within a few hundred parsecs of the Sun, with the most distant at a few thousand. The word ''parsec'' is a portmanteau of "parallax of one second" and was coined by the British astronomer Herbert Hall Turner in 1913 to make calculations of astronomical distances from only raw observational data easy for astronomers. Partly for this reason, it is the unit preferred in astronomy and astrophysics, though the light-year remains prominent in popula ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
