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Radio-quiet Neutron Star
A radio-quiet neutron star is a neutron star that does not seem to emit radio emissions, but is still visible to Earth through electromagnetic radiation at other parts of the spectrum, particularly X-rays and gamma rays. Background Most detected neutron stars are pulsars, and emit radio-frequency electromagnetic radiation. About 700 radio pulsars are listed in the Princeton catalog, and all but one emit radio waves at the 400 MHz and 1400 MHz frequencies. That exception is Geminga, which is radio quiet at frequencies above 100 MHz, but is a strong emitter of X-rays and gamma rays. In all, ten bodies have been proposed as rotation-powered neutron stars that are not visible as radio sources, but are visible as X-ray and gamma ray sources. Indicators that they are indeed neutron stars include them having a high X-ray to lower frequencies emission ratio, a constant X-ray emission profile, and coincidence with a gamma ray source. Hypotheses Quark stars, hypothetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Star Illustrated
The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nuclear fission in 1938, the first self-sustaining nuclear reactor (Chicago Pile-1, 1942) and the first nuclear weapon (Trinity (nuclear test), Trinity, 1945). Neutrons are found, together with a similar number of protons in the atomic nucleus, nuclei of atoms. Atoms of a chemical element that differ only in neutron number are called isotopes. Free neutrons are produced copiously in nuclear fission and nuclear fusion, fusion. They are a primary contributor to the nucleosynthesis of chemical elements within stars through fission, fusion, and neutron capture processes. Neutron stars, formed from massive collapsing stars, consist of neutrons at the density of atomic nuclei but a total mass more than the Sun. Neutron properties and interactions ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft Gamma Repeater
A soft gamma repeater (SGR) is an astronomical object which emits large bursts of gamma-rays and X-rays at irregular intervals. It is conjectured that they are a type of magnetar or, alternatively, neutron stars with fossil disks around them. History On March 5, 1979 a powerful gamma-ray burst was noted. As a number of receivers at different locations in the Solar System saw the burst at slightly different times, its direction could be determined, and it was shown to originate from near a supernova remnant in the Large Magellanic Cloud. Over time it became clear that this was not a normal gamma-ray burst. The photons were less energetic in the soft gamma-ray and hard X-ray range, and repeated bursts came from the same region. Astronomer Chryssa Kouveliotou of the Universities Space Research Association (USRA) at NASA's Marshall Space Flight Center decided to test the hypothesis that soft gamma repeaters were magnetars. According to the hypothesis, the bursts would cause the ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRAS 00500+6713
IRAS 00500+6713 is the catalogued infrared source for an unusual nebula in Cassiopeia, while the central star has a designation WD J005311, with the whole system designated as Pa 30. The central star and its surrounding shell were created by the supernova seen in the year 1181 (SN 1181) as reported by Chinese and Japanese observers. Both the nebula and central star have unique and extreme properties, pointing to their creation by a rare type Iax supernova, where two ultra-dense white dwarfs in-spiral to a collision and explosion. The Pa 30 system was discovered in 2013 by amateur astronomer Dana Patchick. It was independently discovered by Dr. Vasili Gvaramadze and colleagues who first realized that the central star has extreme properties and proposed that it was created from a merger of two white dwarfs. The star exhibits record-breaking wind speeds of 16,000 km/s and temperatures near 200,000 K. The central star, might be a rapidly-rotating super-Chandrasekhar wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotating Radio Transient
Rotating radio transients (RRATs) are sources of short, moderately bright, radio pulses, which were first discovered in 2006. RRATs are thought to be pulsars, i.e. rotating magnetised neutron stars which emit more sporadically and/or with higher pulse-to-pulse variability than the bulk of the known pulsars. The working definition of what a RRAT is, is a pulsar which is more easily discoverable in a search for bright single pulses, as opposed to in Fourier domain searches so that 'RRAT' is little more than a label (of how they are discovered) and does not represent a distinct class of objects from pulsars. over 100 have been reported. General characteristics Pulses from RRATs are short in duration, lasting from a few milliseconds. The pulses are comparable to the brightest single pulses observed from pulsars with flux densities of a few Jansky at 1.4 GHz. Andrew Lyne, a radio astronomer involved in the discovery of RRATs, "guesses that there are only a few dozen brighter radio s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Star Merger
A neutron star merger is the stellar collision of neutron stars. When two neutron stars fall into mutual orbit, they gradually inspiral, spiral inward due to the loss of energy emitted as gravitational radiation. When they finally meet, their merger leads to the formation of either a more massive neutron star, or—if the mass of the remnant exceeds the Tolman–Oppenheimer–Volkoff limit—a black hole. The merger can create a magnetic field that is trillions of times stronger than that of Earth in a matter of one or two milliseconds. The immediate event creates a gamma-ray burst#Short gamma-ray bursts, short gamma-ray burst visible over hundreds of millions, or even billions of light years. The merger of neutron stars momentarily creates an environment of such extreme neutron flux that the r-process, ''r''-process can occur. This reaction accounts for the nucleosynthesis of around half of the isotopes in elements heavier than iron. The mergers also produce kilonovae, which ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PKS 1209-51/52
{{disambig ...
PKS may refer to: * Pammal K. Sambandam, a 2002 Tamil language comedy film * Państwowa Komunikacja Samochodowa, Polish transport organization * Parkstone railway station, station code * Phi Kappa Sigma International Fraternity * Parkes Catalogue of Radio Sources, an astronomical catalogue * Polyketide synthases, enzymes * Prosperous Justice Party (''Partai Keadilan Sejahtera''), Indonesia * Serbian Chamber of Commerce * Pallister-Killian syndrome, a rare genetic disorder which is caused by additional 4 copies of the short arm of chromosome 12 Chromosome 12 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 12 spans about 133 million base pairs (the building material of DNA) and represents between 4 and 4.5 percent of the tot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1E 1207
1E or 1-E may refer to: * 1st meridian east, a longitude coordinate * ISS 1E * Astra 1E, a communications satellite owned and operated by SES, and launched in 1995 * California Proposition 1E (2009), a defeated California ballot proposition * 1E, UIC classification of the 2-10-0 train arrangement * 1E, a designator of celestial objects discovered via Einstein Observatory * 1E, inc - Software Company specializing in Digital Employee Experience (DEX) Gartner Gartner, Inc. is an American research and advisory firm focusing on business and technology topics. Gartner provides its products and services through research reports, conferences, and consulting. Its clients include large corporations, gover ... See also * List of highways numbered 1 * E1 (other) {{Letter–number combination disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puppis A
Puppis A (Pup A) is a supernova remnant (SNR) about 100 light-years in diameter and roughly 6500–7000 light-years distant. Its apparent angular diameter is about 1 degree. The light of the supernova explosion reached Earth approximately 3700 years ago. Although it overlaps the Vela Supernova Remnant, it is four times more distant. A hypervelocity neutron star known as the Cosmic Cannonball has been found in this SNR. Puppis X-1 Puppis X-1 (Puppis A) was discovered by a Skylark flight in October 1971, viewed for 1 min with an accuracy ≥ 2 arcsec, probably at 1M 0821-426, with Puppis A ( RA 08h 23m 08.16s Dec -42° 41′ 41.40″) as the likely visual counterpart. Puppis A is one of the brightest X-ray sources in the X-ray sky. Its X-ray designation is 2U 0821-42. Gallery Image:Puppis labeled.jpg, wide-field composite view of the supernova remnant Puppis A (X-rays from ROSAT ROSAT (short for Röntgensatellit; in German X-rays are called Röntgenstrahlen, in honour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RX J0822-4300
Rx or most commonly refers to a medical prescription. RX, Rx, , or rx may also refer to: Arts and entertainment * ' or ''Rx'', a novel by Elizabeth J. Braswell writing as Tracy Lynn * Rx (band), an industrial rock band * ''Rx'', a 2016 album by Ryan Beaver * ''Rx'', a 2024 album by Galantis * " Rx (Medicate)", a song by Canadian rock band Theory of a Deadman * "rX" (''The Gifted''), an episode of the television series ''The Gifted'' * '' Kamen Rider Black RX'', a Japanese superhero television series * ''Rx'' (film), a 2005 romantic thriller film Science and technology Computing and electronics * Rx (receive, receiver or reception), in various telecommunications applications ** Rx, the receive signal in the RS-232 serial communication standard * Rx, the remote procedure call mechanism used by the Andrew File System * RX, the audio repair software by iZotope * Radeon RX series, a series of graphics products in the AMD Radeon 400 series * Reactive extensions, originally for .N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. There are two common routes to a supernova: either a massive star may run out of fuel, ceasing to generate fusion energy in its core, and collapsing inward under the force of its own gravity to form a neutron star or a black hole; or a white dwarf star may accrete material from a companion star until it reaches a critical mass and undergoes a thermonuclear explosion. In either case, the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s) and a strong shock wave forms ahead of the ejecta. That heats the upstream plasma up to temperatures well above millions of K. The shock continuou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RX J0720
Rx or most commonly refers to a medical prescription. RX, Rx, , or rx may also refer to: Arts and entertainment * ' or ''Rx'', a novel by Elizabeth J. Braswell writing as Tracy Lynn * Rx (band), an industrial rock band * ''Rx'', a 2016 album by Ryan Beaver * ''Rx'', a 2024 album by Galantis * " Rx (Medicate)", a song by Canadian rock band Theory of a Deadman * "rX" (''The Gifted''), an episode of the television series ''The Gifted'' * '' Kamen Rider Black RX'', a Japanese superhero television series * ''Rx'' (film), a 2005 romantic thriller film Science and technology Computing and electronics * Rx (receive, receiver or reception), in various telecommunications applications ** Rx, the receive signal in the RS-232 serial communication standard * Rx, the remote procedure call mechanism used by the Andrew File System * RX, the audio repair software by iZotope * Radeon RX series, a series of graphics products in the AMD Radeon 400 series * Reactive extensions, originally for .N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
