Eta Cassiopeiae
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Eta Cassiopeiae
Eta Cassiopeiae (η Cassiopeiae, abbreviated Eta Cas, η Cas) is a binary star system in the northern constellation of Cassiopeia. Its binary nature was first discovered by William Herschel in August 1779. Based upon parallax measurements, the distance to this system is from the Sun. The two components are designated Eta Cassiopeiae A (officially named Achird , the traditional name for the system) and B. Nomenclature ''η Cassiopeiae'' ( Latinised to ''Eta Cassiopeiae'') is the system's Bayer designation. The designations of the two constituents as ''Eta Cassiopeiae A'' and ''B'' derive from the convention used by the Washington Multiplicity Catalog (WMC) for star systems, and adopted by the International Astronomical Union (IAU). The proper name ''Achird'' was apparently first applied to Eta Cassiopeiae in the Skalnate Pleso Atlas of the Heavens published in 1950, but is not known prior to that. Richard Hinckley Allen gives no historical names for the star ...
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Eta Cassiopeiae
Eta Cassiopeiae (η Cassiopeiae, abbreviated Eta Cas, η Cas) is a binary star system in the northern constellation of Cassiopeia. Its binary nature was first discovered by William Herschel in August 1779. Based upon parallax measurements, the distance to this system is from the Sun. The two components are designated Eta Cassiopeiae A (officially named Achird , the traditional name for the system) and B. Nomenclature ''η Cassiopeiae'' ( Latinised to ''Eta Cassiopeiae'') is the system's Bayer designation. The designations of the two constituents as ''Eta Cassiopeiae A'' and ''B'' derive from the convention used by the Washington Multiplicity Catalog (WMC) for star systems, and adopted by the International Astronomical Union (IAU). The proper name ''Achird'' was apparently first applied to Eta Cassiopeiae in the Skalnate Pleso Atlas of the Heavens published in 1950, but is not known prior to that. Richard Hinckley Allen gives no historical names for the star ...
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Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. The 48 traditional Western constellations are Greek. They are given in Aratus' work ''Phenomena'' and Ptolemy's ''Almagest'', though their origin probably predates these works by several centuries. Constellation ...
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Asterism (astronomy)
An asterism is an observed pattern or group of stars in the sky. Asterisms can be any identified pattern or group of stars, and therefore are a more general concept than the formally defined 88 constellations. Constellations are based on asterisms, but unlike asterisms, constellations outline and today completely divide the sky and all its celestial objects into regions around their central asterisms. For example, the asterism known as the Big Dipper comprises the seven brightest stars in the constellation Ursa Major. Another is the asterism of the Southern Cross, within the constellation of Crux. Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with the night sky. ...
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Legs (Chinese Constellation)
The Legs mansion (奎宿, pinyin: Kuí Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the western mansions of the White Tiger The white tiger or bleached tiger is a leucistic pigmentation variant of the Mainland tiger. It is reported in the wild from time to time in the Indian states of Madhya Pradesh, Assam, West Bengal, Bihar, Odisha, in the Sunderbans region and .... Cultural significance In East Asian cultures, the Legs mansion (Kuí Xiù) represents wisdom, scholarship and literature. A notable example is a structure known as "Kuiwen Pavilion" (奎文閣) in the many Confucius temples in China and other East Asian countries. Asterisms See also * Kui Xing {{Chinese constellation Chinese constellations ...
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Chinese Astronomy
Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the mid-Shang dynasty. The core of the "mansion" (宿 ''xiù'') system also took shape around this period, by the time of King Wu Ding (1250–1192 BCE). Detailed records of astronomical observations began during the Warring States period (fourth century BCE) and flourished from the Han period onward. Chinese astronomy was equatorial, centered on close observation of circumpolar stars, and was based on different principles from those in traditional Western astronomy, where heliacal risings and settings of zodiac constellations formed the basic ecliptic framework. Joseph Needham has described the ancient Chinese as the most persistent and accurate obser ...
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Multiple Star
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a ''star cluster'' or ''galaxy'', although, broadly speaking, they are also star systems. Star systems are not to be confused with planetary systems, which include planets and similar bodies (such as comets). A star system of two stars is known as a ''binary star'', ''binary star system'' or ''physical double star''. If there are no tidal effects, no perturbation from other forces, and no transfer of mass from one star to the other, such a system is stable, and both stars will trace out an elliptical orbit around the barycenter of the system indefinitely. ''(See Two-body problem)''. Examples of binary systems are Sirius, Procyon and Cygnus X-1, the last of which probably consists of a star and a black hole. Multiple star systems A multiple star system consists of three or more stars that appear f ...
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Working Group On Star Names
The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education, Outreach and Heritage. The IAU states that it is keen to make a distinction between the terms ''name'' and ''designation''. To the IAU, ''name'' refers to the (usually colloquial) term used for a star in everyday conversation, while ''designation'' is solely alphanumerical, and used almost exclusively in official catalogues and for professional astronomy. (The WGSN notes that transliterated Bayer designations (e.g., Tau Ceti) are considered a special historical case and are treated as designations.) Terms of reference The terms of reference for the WGSN for the period 2016–2018 were approved by the IAU Executive Committee at its meeting on 6 May 2016. In summary, these are to: * establish IAU guidelines for the proposal and a ...
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Their Lore And Meaning
In Modern English, ''they'' is a third-person pronoun relating to a grammatical subject. Morphology In Standard Modern English, ''they'' has five distinct word forms: * ''they'': the nominative (subjective) form * ''them'': the accusative (objective, called the 'oblique'.) and a non-standard determinative form. * ''their:'' the dependent genitive (possessive) form * ''theirs'': independent genitive form * ''themselves'': prototypical reflexive form *''themself'': derivative reflexive form (nonstandard; now chiefly used instead of "himself or herself" as a reflexive epicenity for ''they'' in pronominal reference to a singular referent) History Old English had a single third-person pronoun '' hē'', which had both singular and plural forms, and ''they'' wasn't among them. In or about the start of the 13th century, ''they'' was imported from a Scandinavian source (Old Norse ''þeir'', Old Danish, Old Swedish ''þer'', ''þair''), where it was a masculine plural demonstr ...
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Richard Hinckley Allen
In astronomy, stars have a variety of different stellar designations and names, including catalogue designations, current and historical proper names, and foreign language names. Only a tiny minority of known stars have proper names; all others have only designations from various catalogues or lists, or no identifier at all. Hipparchus in the 2nd century BC enumerated about 850 naked-eye stars. Johann Bayer in 1603 listed about twice this number. Only in the 19th century did star catalogues list the naked-eye stars exhaustively. The Bright Star Catalogue, which is a star catalogue listing all stars of apparent magnitude 6.5 or brighter, or roughly every star visible to the naked eye from Earth, contains 9,096 stars. The most voluminous modern catalogues list on the order of a billion stars, out of an estimated total of 200 to 400 billion in the Milky Way. Proper names may be historical, often transliterated from Arabic or Chinese names. Such transliterations can vary so there ...
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Skalnate Pleso Atlas Of The Heavens
The ''Skalnaté Pleso Atlas of the Heavens'' (''Atlas Coeli Skalnaté Pleso 1950.0'') is a set of 16 Star chart, celestial charts covering the entire sky. It is named after the Skalnaté pleso observatory, Skalnaté Pleso Observatory in Slovakia where it was produced. The first versions were published by the Czechoslovak Astronomical Society in 1948; later that year, Sky Publishing Corporation acquired the copyright and began publication in the United States. The charts were hand-drawn by Antonín Bečvář. At the time it was first published, the ''Atlas Coeli'' was unique in that it contained essentially all non-stellar objects (star clusters, galaxies etc.) that were visible in an 8-inch telescope, in addition to stars brighter than apparent magnitude, magnitude 7.75. Until the mid-1970s when it went out of print, the ''Atlas'' was extremely popular among amateur astronomers, especially those engaged in comet hunting and the study of variable stars. The ''Atlas Coeli'' was als ...
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International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded in 1919 and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. As of 2018, the Union had over 13,700 individual members, spanning 90 countries, and 82 national members. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ...
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Star System
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a '' star cluster'' or '' galaxy'', although, broadly speaking, they are also star systems. Star systems are not to be confused with planetary systems, which include planets and similar bodies (such as comets). A star system of two stars is known as a '' binary star'', ''binary star system'' or ''physical double star''. If there are no tidal effects, no perturbation from other forces, and no transfer of mass from one star to the other, such a system is stable, and both stars will trace out an elliptical orbit around the barycenter of the system indefinitely. ''(See Two-body problem)''. Examples of binary systems are Sirius, Procyon and Cygnus X-1, the last of which probably consists of a star and a black hole. Multiple star systems A multiple star system consists of three or more stars that ...
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