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GRB 170817A
GW170817 was a gravitational wave (GW) observed by the LIGO and Virgo detectors on 17 August 2017, originating within the shell elliptical galaxy NGC 4993, about 144 million light years away. The wave was produced by the last moments of the inspiral of a binary pair of neutron stars, ending with their merger. , it is the only GW detection to be definitively correlated with any electromagnetic observation. Unlike the five prior GW detections—which were of merging black holes and thus not expected to have detectable electromagnetic signals—the aftermath of this merger was seen across the electromagnetic spectrum by 70 observatories on 7 continents and in space, marking a significant breakthrough for multi-messenger astronomy. The discovery and subsequent observations of GW170817 were given the Breakthrough of the Year award for 2017 by the journal ''Science''. GW170817 had an audible duration of approximately 100 seconds and exhibited the characteristic intensity and f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
J2000
In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodies) can be used to generate an ephemeris, a table of values giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Direction Finding
Direction finding (DF), radio direction finding (RDF), or radiogoniometry is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertent source, a naturally-occurring radio source, or an illicit or enemy system. Radio direction finding differs from radar in that only the direction is determined by any one receiver; a radar system usually also gives a distance to the object of interest, as well as direction. By triangulation, the location of a radio source can be determined by measuring its direction from two or more locations. Radio direction finding is used in radio navigation for ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. During the Second World War, radio direction finding was used by both sides to locate and direct aircraft, surface ships, and submarines. RDF systems can be used w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Science (magazine)
''Science'' 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'' cover the full range of scientific disciplines. According to the '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
The Mercury News
''The Mercury News'' (formerly ''San Jose Mercury News'', often locally known as ''The Merc'') is a morning daily newspaper published in San Jose, California, in the San Francisco Bay Area. It is published by the Bay Area News Group, a subsidiary of Media News Group which in turn is controlled by Alden Global Capital, a vulture fund. , it was the List of newspapers in the United States#Top 10 newspapers by circulation, fifth largest daily newspaper in the United States, with a daily circulation of 611,194. , the paper has a circulation of 324,500 daily and 415,200 on Sundays. this further declined. The Bay Area News Group no longer reports its circulation, but rather "readership". For 2021, they reported a "readership" of 312,700 adults daily. First published in 1851, the ''Mercury News'' is the last remaining English-language daily newspaper covering the Santa Clara Valley. It became the ''Mercury News'' in 1983 after a series of mergers. During much of the 20th century, it wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
The New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of the longest-running newspapers in the United States, the ''Times'' serves as one of the country's Newspaper of record, newspapers of record. , ''The New York Times'' had 9.13 million total and 8.83 million online subscribers, both by significant margins the List of newspapers in the United States, highest numbers for any newspaper in the United States; the total also included 296,330 print subscribers, making the ''Times'' the second-largest newspaper by print circulation in the United States, following ''The Wall Street Journal'', also based in New York City. ''The New York Times'' is published by the New York Times Company; since 1896, the company has been chaired by the Ochs-Sulzberger family, whose current chairman and the paper's publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Garching Bei München
Garching bei München (, ''Garching near Munich'') or Garching is a city in Bavaria, near Munich. It is the home of several research institutes and university departments, located at Campus Garching. History Spatial urban planning Garching was small Bavarian village, until the Free State of Bavaria decided to implement a technology and urban planning policy whereby science should be clustered north of Munich. This urban planning policy was in line with the principles advanced by the International Congress of Modernist Architects (CIAM) in the 1933 Athens Charter. Garching was redeveloped in three spatially separated parts, to cover the urban functions of industry, habitation, and research. In 1959 a new residential quarter for Max Planck Society employees was constructed. In 1960 the Max Planck Institute for Plasma Physics was established in Garching. In 1963 Technical University of Munich (TUM) published plans, whereby some TUM institutes would be moved to Garching. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
European Southern Observatory
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 member states for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs over 750 staff members and receives annual member state contributions of approximately €162 million. Its observatories are located in northern Chile. ESO has built and operated some of the largest and most technologically advanced telescopes. These include the 3.6 m New Technology Telescope, an early pioneer in the use of active optics, and the Very Large Telescope (VLT), which consists of four individual 8.2 m telescopes and four smaller auxiliary telescopes which can all work together or separately. The Atacama Large Millimeter Array observes the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
National Press Club (United States)
The National Press Club is a Professional association, professional organization and social community in Washington, D.C. for journalists and communications professionals. It hosts public and private gatherings with invited speakers from public life. The club also offers event space to outside groups to host business meetings, news conferences, industry gatherings, and social events. It was founded in 1908. The club has been visited by most Presidents of the United States, U.S. presidents; since Warren Harding, many have also been members and spoken from the club's podium. Others who have appeared at the club include monarchs, prime ministers, premiers, members of United States Congress, Congress, Cabinet of the United States, Cabinet officials, ambassadors, scholars, entertainers, business leaders, and athletes. The club's emblem is the owl, in deference to wisdom, awareness and nights spent working. History Founding On March 12, 1908, 32 newspapermen met at the Washington Cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
David Reitze
David Howard Reitze (born 6 January 1961) is an American laser physicist who is professor of physics at the University of Florida and served as the scientific spokesman of the Laser Interferometer Gravitational-Wave Observatory ( LIGO) experiment in 2007-2011. In August 2011, he took a leave of absence from the University of Florida to be the Executive Director of LIGO, stationed at the California Institute of Technology, Pasadena, California. He obtained his BA in 1983 from Northwestern University, his PhD in physics from the University of Texas at Austin in 1990, and had positions at Bell Communications Research and Lawrence Livermore National Laboratory, before taking his faculty position at the University of Florida. He is a Fellow of the American Physical Society, the Optical Society, and the American Association for the Advancement of Science. An expert in ultrafast optics and laser spectroscopy, he now specialises in laser-based interferometric gravitational wave det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Kilonova
A kilonova (also called a macronova) is a transient astronomical event that occurs in a compact star, compact binary system when two neutron stars (BNS) or a neutron star and a black hole collide. The kilonova, visible over the weeks and months following the merger, is an isotropically expanding luminous afterglow of electromagnetic radiation emitted by the radioactive decay of r-process, ''r''-process nuclei synthesized by—and then ejected from—the initial cataclysmic event. The high sphericity of kilonovae through its early epochs was deduced from the blackbody nature of the spectrum observed for the most important recorded neutron star merger, BNS merger, GW170817, GW170817/AT2017gfo. History The existence of thermal transient events from neutron star mergers was first introduced by Li & Bohdan Paczyński, Paczyński in 1998. The radioactive glow arising from the merger ejecta was originally called mini-supernova, as it is to the brightness of a typical supernova, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Astronomical Transient
Time-domain astronomy is the study of how astronomical objects change with time. Said to have begun with Galileo's '' Letters on Sunspots'', the field has now naturally expanded to encompass variable objects beyond the Solar System. Temporal variation may originate from movement of the source, or changes in the object itself. Common targets include novae, supernovae, pulsating stars, flare stars, blazars and active galactic nuclei. Optical time domain surveys include OGLE, HAT-South, PanSTARRS, SkyMapper, ASAS, WASP, CRTS, GOTO, and the forthcoming LSST at the Vera C. Rubin Observatory. Time-domain astronomy studies transient astronomical events ("''transients''"), which include various types of variable stars, including periodic, quasi-periodic, high proper motion stars, and lifecycle events (supernovae, kilonovae) or other changes in behavior or type. Non-stellar transients include asteroids, planetary transits and comets. Transients characterize astronomical o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
