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Neutron Star Merger
A neutron star merger is a type of stellar collision. It occurs in a fashion similar to the rare brand of type Ia supernovae resulting from merging white dwarf stars. When two neutron stars orbit each other closely, they gradually spiral inward due to gravitational radiation. When the two neutron stars meet, their merger leads to the formation of either a more massive neutron star, or a black hole (depending on whether the mass of the remnant exceeds the Tolman–Oppenheimer–Volkoff limit). The merger can also create a magnetic field that is trillions of times stronger than that of Earth in a matter of one or two milliseconds. These events are believed to create short gamma-ray bursts. The merger of binary neutron stars is believed to be the origin of most elements with large atomic weights - the r-process elements. The mergers are also believed to produce kilonovae, which are transient sources of fairly isotropic longer wave electromagnetic radiation due to the radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIGO
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large observatories were built in the United States with the aim of detecting gravitational waves by laser interferometry. These observatories use mirrors spaced four kilometers apart which are capable of detecting a change of less than one ten-thousandth the charge diameter of a proton. (that is, to Proxima Centauri at ). The initial LIGO observatories were funded by the United States National Science Foundation (NSF) and were conceived, built and are operated by Caltech and MIT. They collected data from 2002 to 2010 but no gravitational waves were detected. The Advanced LIGO Project to enhance the original LIGO detectors began in 2008 and continues to be supported by the NSF, with important contributions from the United Kingdom's Science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Astrophysical Journal
''The Astrophysical Journal'', often abbreviated ''ApJ'' (pronounced "ap jay") in references and speech, is a peer-reviewed Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer review ... scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and James Edward Keeler. The journal discontinued its print edition and became an electronic-only journal in 2015. Since 1953 ''The Astrophysical Journal Supplement Series'' (''ApJS'') has been published in conjunction with ''The Astrophysical Journal'', with generally longer articles to supplement the material in the journal. It publishes six volumes per year, with two 280-page issues per volume. ''The Astrophysical Journal Letters'' (''ApJL''), established in 1967 by Subrahmanyan Chandrasekhar as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SSS17a
GW 170817 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 17 August 2017, originating from the shell elliptical galaxy . The signal was produced by the last minutes of a binary pair of neutron stars' inspiral process, ending with a merger. It is the first GW observation that has been confirmed by non-gravitational means. Unlike the five previous GW detections, which were of merging black holes not expected to produce a detectable electromagnetic signal, the aftermath of this merger was also seen by 70 observatories on 7 continents and in space, across the electromagnetic spectrum, marking a significant breakthrough for multi-messenger astronomy. The discovery and subsequent observations of GW 170817 were given the Breakthrough of the Year award for 2017 by the journal ''Science''. The gravitational wave signal, designated GW 170817, had a duration of approximately 100 seconds, and shows the characteristics in i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GRB 170817A
GW 170817 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 17 August 2017, originating from the shell elliptical galaxy . The signal was produced by the last minutes of a binary pair of neutron stars' inspiral process, ending with a merger. It is the first GW observation that has been confirmed by non-gravitational means. Unlike the five previous GW detections, which were of merging black holes not expected to produce a detectable electromagnetic signal, the aftermath of this merger was also seen by 70 observatories on 7 continents and in space, across the electromagnetic spectrum, marking a significant breakthrough for multi-messenger astronomy. The discovery and subsequent observations of GW 170817 were given the Breakthrough of the Year award for 2017 by the journal ''Science''. The gravitational wave signal, designated GW 170817, had a duration of approximately 100 seconds, and shows the characteristics in i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydra (constellation)
Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees, and also the longest at over 100 degrees. Its southern end borders Libra and Centaurus and its northern end borders Cancer. It was included among the 48 constellations listed by the 2nd century astronomer Ptolemy. Commonly represented as a water snake, it straddles the celestial equator. History and mythology Western mythology The Greek constellation of Hydra is an adaptation of a Babylonian constellation: the MUL.APIN includes a "serpent" constellation (MUL.DINGIR.MUŠ) that loosely corresponds to Hydra. It is one of two Babylonian "serpent" constellations (the other being the origin of the Greek Serpens), a mythological hybrid of serpent, lion and bird. The shape of Hydra resembles a twisting snake, and features as such in some Greek myths. One myth associates it with a water snake that a crow served Apollo in a cup when it was sent to fetch water; Apollo saw through the fraud, and angr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptical Galaxy
An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The Realm of the Nebulae'', with their intermediate scale disks, a subset of the "early-type" galaxy population. Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity, and they tend to be surrounded by large numbers of globular clusters. Elliptical galaxies are believed to make up approximately 10–15% of galaxies in the Virgo Supercluster, and they are not the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters. Elliptical galaxies range in size from dwarf ellipticals with tens of millions of stars, to supergiants of over one hundred trillion stars that dominate their galaxy clusters. Original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4993
NGC 4993 (also catalogued as NGC 4994 in the New General Catalogue) is a lenticular galaxy located about 140 million light-years away in the constellation Hydra. It was discovered on 26 March 1789 by William Herschel and is a member of the NGC 4993 Group. NGC 4993 is the site of GW170817, the first astronomical event detected in both electromagnetic and gravitational radiation, the collision of two neutron stars, a discovery given the Breakthrough of the Year award for 2017 by the journal ''Science''. Detecting a gravitational wave event associated with the gamma-ray burst provided direct confirmation that binary neutron star collisions produce short gamma-ray bursts. Physical characteristics NGC 4993 has several concentric shells of stars and large dust lane with diameter of approximately a few kiloparsecs which surrounds the nucleus and is stretched out into an "s" shape. The dust lane appears to be connected to a small dust ring with a diameter of ~. These features in NGC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GW170817
GW 170817 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 17 August 2017, originating from the shell elliptical galaxy . The signal was produced by the last minutes of a binary pair of neutron stars' inspiral process, ending with a merger. It is the first GW observation that has been confirmed by non-gravitational means. Unlike the five previous GW detections, which were of merging black holes not expected to produce a detectable electromagnetic signal, the aftermath of this merger was also seen by 70 observatories on 7 continents and in space, across the electromagnetic spectrum, marking a significant breakthrough for multi-messenger astronomy. The discovery and subsequent observations of GW 170817 were given the Breakthrough of the Year award for 2017 by the journal ''Science''. The gravitational wave signal, designated GW 170817, had a duration of approximately 100 seconds, and shows the characteristics in inten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy (magazine)
''Astronomy'' is a monthly American magazine about astronomy. Targeting amateur astronomers, it contains columns on sky viewing, reader-submitted astrophotographs, and articles on astronomy and astrophysics for general readers. History ''Astronomy'' is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. ''Astronomy''’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general. ''Astronomy'' was founded in 1973 by Stephen A. Walther, a graduate of the University of Wisconsin–Stevens Point and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
