Leon Campbell (astronomer)
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Leon Campbell (astronomer)
Leon Campbell (January 20, 1881 in Cambridge, MassachusettsCAMPBELL, Leon
in '''' (1926 edition); p. 409
– May 10, 1951) was an American . He is noted for his observations of s at the . He served as Recorder of Obs ...
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Cambridge, Massachusetts
Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, 2020 U.S. census was 118,403, making it the most populous city in the county, the List of municipalities in Massachusetts, fourth-largest in Massachusetts behind Boston, Worcester, Massachusetts, Worcester, and Springfield, Massachusetts, Springfield, and List of cities in New England by population, ninth-most populous in New England. The city was named in honor of the University of Cambridge in Cambridge, England, which was an important center of the Puritans, Puritan theology that was embraced by the town's founders. Harvard University, an Ivy League university founded in Cambridge in 1636, is the oldest institution of higher learning in the United States. The Massachusetts Institute of Technology (MIT), Lesley University, and Hult Inte ...
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Who's Who In America
Marquis Who's Who, also known as A.N. Marquis Company ( or ), is an American publisher of a number of directories containing short biographies. The books usually are entitled ''Who's Who in...'' followed by some subject, such as ''Who's Who in America'', ''Who's Who of American Women'', ''Who's Who in Asia'', ''Who's Who in the World'', ''Who's Who in Science and Engineering'', ''Who's Who in American Politics'', etc. Often, ''Marquis Who's Who'' books are found in the reference section of local libraries, at corporate libraries, and are also used for research by universities. In 2005, while Marquis was owned by News Communications, Inc., publishers of '' The Hill''; ''The New York Times'' referred to the sixtieth edition of ''Who's Who in America'' as . Marquis states in its preface that ''Who's Who in America'' . Entries in ''Marquis Who's Who'' books list career and personal data for each biography, including birth date and place, names of parents and family members, educatio ...
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Springer Publishing
Springer Publishing Company is an American publishing company of academic journals and books, focusing on the fields of nursing, gerontology, psychology, social work, counseling, public health, and rehabilitation (neuropsychology). It was established in 1951 by Bernhard Springer, a great-grandson of Julius Springer, and is based in Midtown Manhattan, New York City. History Springer Publishing Company was founded in 1950 by Bernhard Springer, the Berlin-born great-grandson of Julius Springer, who founded Springer Science+Business Media, Springer-Verlag (now Springer Science+Business Media). Springer Publishing's first landmark publications included ''Livestock Health Encyclopedia'' by R. Seiden and the 1952 ''Handbook of Cardiology for Nurses''. The company's books soon branched into other fields, including medicine and psychology. Nursing publications grew rapidly in number, as Modell's ''Drugs in Current Use'', a small annual paperback, sold over 150,000 copies over several edi ...
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Astronomer
An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galaxies – in either observational astronomy, observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, Sun, solar astronomy, the Star formation, origin or stellar evolution, evolution of stars, or the galaxy formation and evolution, formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. Types Astronomers typically fall under either of two main types: observational astronomy, observational and theoretical astronomy, theoretical. Observational astronomers make direct observations of Astronomical object, celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate Con ...
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Variable Star
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: * ''Intrinsic variables'', whose luminosity actually changes periodically; for example, because the star swells and shrinks. * ''Extrinsic variables'', whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star has an orbiting companion that sometimes eclipses it. Many, possibly most, stars exhibit at least some oscillation in luminosity: the energy output of the Sun, for example, varies by about 0.1% over an 11-year solar cycle. Discovery An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago may be the oldest preserved historical document of the discovery of a variable star, the eclipsing binary Algol. A ...
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Harvard College Observatory
The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United States, and was founded in 1839. With the Smithsonian Astrophysical Observatory, it forms part of the Center for Astrophysics Harvard & Smithsonian. HCO houses the Harvard Plate Stacks, a collection of approximately 600,000 astronomical plates taken between the mid-1880s and 1989 (with a gap from 1953–1968). This 100-year coverage is a unique resource for studying temporal variations in the universe. The Digital Access to a Sky Century @ Harvard project scanned and 429,274 direct image plates, leaving nearly 200,000 spectra and other photographic plates yet to be digitized. In 2024, a new database, StarGlass, was created to combine the scientific data from the plates with the Plate Stack's archival holdings. History In 1839, the Ha ...
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AAVSO
The American Association of Variable Star Observers (AAVSO) is an international nonprofit organization. Founded in 1911, the organization focuses on coordinating, analyzing, publishing, and archiving variable star observations made largely by amateur astronomers. The AAVSO creates records that establish light curves depicting the variation in brightness of a star over time. The AAVSO makes these records available to professional astronomers, researchers, and educators. Professional astronomers do not have the resources to monitor every variable star. Hence, astronomy is one of the few sciences where amateurs can make significant contributions to research. In 2011, the 100th year of the AAVSO's existence, the twenty-millionth variable star observation was received into their database. The AAVSO International Database (AID) has stored over thirty-five million observations as of 2019. The organization receives nearly 1,000,000 observations annually from an estimated amount of 2,000 ...
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Campbell (lunar Crater)
Campbell is a large Lunar craters, lunar impact crater that is located in the northern hemisphere on the Far side (Moon), far side of the Moon. It lies to the southwest of the walled plain D'Alembert (crater), D'Alembert, an even larger formation. If Campbell were located on the near side of the Moon as seen from the Earth, it would form one of the largest visible craters, being slightly larger than Schickard (crater), Schickard. It is bordered by several craters of note, with Wiener (crater), Wiener to the southwest, Von Neumann (crater), Von Neumann just to the south, Ley (crater), Ley overlying the southeast rim, and Pawsey (crater), Pawsey to the west. This formation has been heavily worn and eroded by a history of impacts, leaving a circular rim that is an irregular ring of ridges and peaks. Multiple small craters lie along the rim and the inner wall, as well as across the interior floor. The most notable of these are Campbell X along the northwest inner rim and Campbell N ne ...
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William Wallace Campbell
William Wallace Campbell (April 11, 1862 – June 14, 1938) was an American astronomer, and director of Lick Observatory from 1901 to 1930. He specialized in spectroscopy. He was the tenth president of the University of California from 1923 to 1930. Biography He was born on a farm in Hancock County, Ohio, the son of Robert Wilson and Harriet Welsh Campbell. After a few years of local schooling he entered in 1882 the University of Michigan to study civil engineering, graduating Bachelor of Science in 1886. Whilst at university he developed his interest in astronomy when he read Simon Newcomb's ''Popular Astronomy''. After graduating he was appointed Professor of Mathematics at the University of Colorado but soon moved back to Michigan as an instructor in astronomy. In 1891 he was invited to work on spectroscopy at Lick Observatory in California. Campbell was a pioneer of astronomical spectroscopy and catalogued the radial velocities of stars. He was also recognized for his work i ...
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1881 Births
Events January * January 1– 24 – Siege of Geok Tepe: Russian troops under General Mikhail Skobelev defeat the Turkomans. * January 13 – War of the Pacific – Battle of San Juan and Chorrillos: The Chilean army defeats Peruvian forces. * January 15 – War of the Pacific – Battle of Miraflores: The Chileans take Lima, capital of Peru, after defeating its second line of defense in Miraflores. * January 24 – William Edward Forster, chief secretary for Ireland, introduces his Coercion Bill, which temporarily suspends habeas corpus so that those people suspected of committing an offence can be detained without trial; it goes through a long debate before it is accepted February 2. Note that Coercion bills had been passed almost annually in the 19th century, with a total of 105 such bills passed from 1801 to 1921. * January 25 – Thomas Edison and Alexander Graham Bell form the Oriental Telephone Company. February * Febru ...
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1951 Deaths
Events January * January 4 – Korean War: Third Battle of Seoul – Chinese and North Korean forces capture Seoul for the second time (having lost the Second Battle of Seoul in September 1950). * January 9 – The Government of the United Kingdom announces abandonment of the Tanganyika groundnut scheme for the cultivation of peanuts in the Tanganyika Territory, with the writing off of £36.5M debt. * January 11 – In the U.S., a top secret report is delivered to U.S. President Truman by his National Security Resources Board, urging Truman to expand the Korean War by launching "a global offensive against communism" with sustained bombing of Red China and diplomatic moves to establish "moral justification" for a U.S. nuclear attack on the Soviet Union. The report will not not be declassified until 1978. * January 15 – In a criminal court in West Germany, Ilse Koch, The "Witch of Buchenwald", wife of the commandant of the Buchenwald concentration camp, is sentenced to li ...
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