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3C 58
3C 58 or 3C58 is a pulsar (designation PSR J0205+6449) and supernova remnant ( pulsar wind nebula) within the Milky Way that is possibly associated with the supernova of 1181. There are, however, signs that indicate that it could be several thousand years old, and thus not associated with that supernova. The object is listed as No. 58 in the Third Cambridge Catalogue of Radio Sources. The pulsar is notable for its very high rate of cooling, which is unexplained by standard theories of neutron star formation. It is hypothesized that extreme conditions in the star's interior cause a high neutrino flux, which carries away the energy so that the star cools. 3C 58 has been proposed as a possible quark star. It is located 2° northeast of ε Cassiopeiae and is estimated to be 10,000 light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distance, astronomical distances and is equivalent to about 9.46 Or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3C58 Chandra
3C 58 or 3C58 is a pulsar (designation PSR J0205+6449) and supernova remnant (pulsar wind nebula) within the Milky Way that is possibly associated with the supernova of 1181. There are, however, signs that indicate that it could be several thousand years old, and thus not associated with that supernova. The object is listed as No. 58 in the Third Cambridge Catalogue of Radio Sources. The pulsar is notable for its very high rate of cooling, which is unexplained by standard theories of neutron star formation. It is hypothesized that extreme conditions in the star's interior cause a high neutrino flux, which carries away the energy so that the star cools. 3C 58 has been proposed as a possible quark star. It is located 2° northeast of ε Cassiopeiae and is estimated to be 10,000 light-years away. Its rotation period is 65.7 ms (so PSR J0205+6449 does not belong to the class of millisecond pulsar A millisecond pulsar (MSP) is a pulsar with a rotational period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SN 1181
First observed between August 4 and August 6, 1181, Chinese and Japanese astronomers recorded the supernova now known as SN 1181 in eight separate texts. One of only nine supernovae in the Milky Way observable with the naked eye in recorded history, it appeared in the constellation Cassiopeia and was visible in the night sky for about 185 days. Pulsar 3C-58 The radio and X-ray pulsar J0205+6449 (also known as 3C 58), which rotates about 15 times per second, has been identified as the possible remnant from this event. If the supernova and pulsar are associated, the star is still rotating about as quickly as it did when it first formed. This is in contrast to the Crab pulsar, known to be the remnant of the SN 1054 supernova in the year 1054, which has lost two-thirds of its rotational energy in essentially the same time span. A paper of radio surveys of 3C 58 published in 2006 indicated that this supernova remnant may be much older and thus not associated with SN 1181. Howe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsars
A pulsar (from ''pulsating radio source'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth (similar to the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays. (See also centrifugal mechanism of acceleration.) The periods of pulsars make them very useful tools for astronomers. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quark Stars
A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All commonly observable matter is composed of up quarks, down quarks and electrons. Owing to a phenomenon known as ''color confinement'', quarks are never found in isolation; they can be found only within hadrons, which include baryons (such as protons and neutrons) and mesons, or in quark–gluon plasmas. There is also the theoretical possibility of more exotic phases of quark matter. For this reason, much of what is known about quarks has been drawn from observations of hadrons. Quarks have various Intrinsic and extrinsic properties, intrinsic physical property, properties, including electric charge, mass, color charge, and spin (physics), spin. They are the only elementary particles in the Standard Model of particle physics to experience all four ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millisecond Pulsar
A millisecond pulsar (MSP) is a pulsar with a rotational period less than about 10 milliseconds. Millisecond pulsars have been detected in radio, X-ray, and gamma ray portions of the electromagnetic spectrum. The leading theory for the origin of millisecond pulsars is that they are old, rapidly rotating neutron stars that have been spun up or "recycled" through accretion of matter from a companion star in a close binary system. For this reason, millisecond pulsars are sometimes called recycled pulsars. Millisecond pulsars are thought to be related to low-mass X-ray binary systems. It is thought that the X-rays in these systems are emitted by the accretion disk of a neutron star produced by the outer layers of a companion star that has overflowed its Roche lobe. The transfer of angular momentum from this accretion event can theoretically increase the rotation rate of the pulsar to hundreds of times per second, as is observed in millisecond pulsars. There has been recent evidence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distance, astronomical distances and is equivalent to about 9.46 Orders of magnitude (numbers)#1012, trillion kilometers (), or 5.88 trillion miles ().One trillion here is long and short scales, taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that Speed of light, light travels in a vacuum in one Julian year (astronomy), Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a Galaxy, galactic scale, especially in public understanding of science, non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Cassiopeiae
Epsilon Cassiopeiae or ε Cassiopeiae, officially named Segin (), is a single star in the northern constellation of Cassiopeia. With an apparent visual magnitude of 3.4, this is one of the brightest stars in the constellation. The distance to this star has been determined directly using parallax measurements, yielding a value of around from the Sun. It is drifting closer with a radial velocity of −8 km/s. Nomenclature ''ε Cassiopeiae'', Latinised to ''Epsilon Cassiopeiae'', is the star's Bayer catalog designation. The star bore the traditional name ''Segin'', which probably originates from an erroneous transcription of ''Seginus'', the traditional name for Gamma Boötis, which itself is of uncertain origin. Different sources report varying pronunciations, with SEG-in the most common but the variants SAY-gin and seg-EEN also appearing. In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quark Star
A quark star is a hypothetical type of compact, exotic star, where extremely high core temperature and pressure has forced nuclear particles to form quark matter, a continuous state of matter consisting of free quarks. Background Some massive stars collapse to form neutron stars at the end of their life cycle, as has been both observed and explained theoretically. Under the extreme temperatures and pressures inside neutron stars, the neutrons are normally kept apart by a degeneracy pressure, stabilizing the star and hindering further gravitational collapse. However, it is hypothesized that under even more extreme temperature and pressure, the degeneracy pressure of the neutrons is overcome, and the neutrons are forced to merge and dissolve into their constituent quarks, creating an ultra-dense phase of quark matter based on densely packed quarks. In this state, a new equilibrium is supposed to emerge, as a new degeneracy pressure between the quarks, as well as repulsive ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flux
Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications to physics. For transport phenomena, flux is a vector quantity, describing the magnitude and direction of the flow of a substance or property. In vector calculus flux is a scalar quantity, defined as the surface integral of the perpendicular component of a vector field over a surface. Terminology The word ''flux'' comes from Latin: ''fluxus'' means "flow", and ''fluere'' is "to flow". As '' fluxion'', this term was introduced into differential calculus by Isaac Newton. The concept of heat flux was a key contribution of Joseph Fourier, in the analysis of heat transfer phenomena. His seminal treatise ''Théorie analytique de la chaleur'' (''The Analytical Theory of Heat''), defines ''fluxion'' as a central quantity and proceeds to derive the now well-known e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrino
A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small ('' -ino'') that it was long thought to be zero. The rest mass of the neutrino is much smaller than that of the other known elementary particles excluding massless particles. The weak force has a very short range, the gravitational interaction is extremely weak due to the very small mass of the neutrino, and neutrinos do not participate in the strong interaction. Thus, neutrinos typically pass through normal matter unimpeded and undetected. Weak interactions create neutrinos in one of three Lepton, leptonic Flavor (particle physics), flavors: electron neutrinos muon neutrinos (), or tau neutrinos (), in association with the corresponding charged lepton. Although neutrinos were long believed to be massless, it is now kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Star
A neutron star is the collapsed core of a massive supergiant star, which had a total mass of between 10 and 25 solar masses, possibly more if the star was especially metal-rich. Except for black holes and some hypothetical objects (e.g. white holes, quark stars, and strange stars), neutron stars are the smallest and densest currently known class of stellar objects. Neutron stars have a radius on the order of and a mass of about 1.4 solar masses. They result from the supernova explosion of a massive star, combined with gravitational collapse, that compresses the core past white dwarf star density to that of atomic nuclei. Once formed, they no longer actively generate heat, and cool over time; however, they may still evolve further through collision or accretion. Most of the basic models for these objects imply that neutron stars are composed almost entirely of neutrons (subatomic particles with no net electrical charge and with slightly larger mass than protons); th ... [...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 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 flux limit of 9 Jy or as no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
