Cor Caroli
Cor Caroli is the traditional name for the binary star designated Alpha Canum Venaticorum, although the International Astronomical Union now regards the name as only applying to the brightest component. Alpha Canum Venaticorum is the brightest point of light in the northern constellation of Canes Venatici. Α Canum Venaticorum is the system's Bayer designation. The brighter of the two stars is designated α2 the fainter α1 Canum Venaticorum. In the western world Alpha Canum Venaticorum had no name until the 17th century, when it was named Cor Caroli, which means "Charles's Heart". There has been some uncertainty whether it was named in honour of King Charles I of England, executed in 1649 during the English Civil War, or of his son, Charles II, who restored the English monarchy to the throne in 1660; the name was coined in 1660 by Sir Charles Scarborough, physician to Charles II, who claimed the star seemed to shine exceptionally brightly on the night of Charles II's return to England. In Star Names, R.
H. Allen claimed that Scarborough suggested the name to Edmond Halley and intended it to refer to Charles II. However, Robert Burnham Jr. notes that "the attribution of the name to Halley appears in a report published by J. E. Bode at Berlin in 1801, but seems to have no other verification". In Star Tales, Ian Ridpath points out that the name's first appearance on a star map was in the 1673 chart of Francis Lamb, who labelled it Cor Caroli Regis Martyris indicating that it was seen as referring to Charles I. In 2016, the International Astronomical Union organized a Working Group on Star Names to catalog and standardize proper names for stars; the WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN. In Chinese, 常陳, meaning Imperial Guards, refers to an asterism consisting of α Canum Venaticorum, 10 Canum Venaticorum, Beta Canum Venaticorum, 6 Canum Venaticorum, 2 Canum Venaticorum, 67 Ursae Majoris; the Chinese name for Alpha Canum Venaticorum itself is 常陳一 From this Chinese name, the name Chang Chen was derived.
Alpha Canum Venaticorum is a binary star with a combined apparent magnitude of 2.81. The two stars are 19.6 arcseconds apart in the sky and are resolved in small telescopes. The system lies 110 light years from the Sun, it marks the northern vertex of the asterism known as the Diamond of Virgo. Α2 Canum Venaticorum has a spectral type of A0, has an apparent visual magnitude which varies between 2.84 and 2.98, with a period of 5.47 days. It is a chemically peculiar star with a strong magnetic field, about 5,000 times as strong as the Earth's, is classified as an Ap/Bp star, its atmosphere has overabundances of some elements, such as silicon and europium. This is thought to be due to some elements sinking down into the star under the force of gravity while others are elevated by radiation pressure; this star is the prototype of a class of variable stars, the so-called α2 Canum Venaticorum variables. The strong magnetic field of these stars is believed to produce starspots of enormous extent. Due to these starspots the brightness of α2 Canum Venaticorum stars varies during their rotation.
Α1 Canum Venaticorum is a F-type main sequence star. It is fainter than its companion and has an apparent visual magnitude of 5.60. Cor Caroli was a United States Navy Crater class cargo ship named after the star
Mu Arae
Mu Arae designated HD 160691 named Cervantes, is a main sequence G-type star 50 light-years away from the Sun in the constellation of Ara. The star has a planetary system with four known extrasolar planets, three of them with masses comparable to that of Jupiter; the system's innermost planet was the first ` hot Neptune' or ` super-Earth'. Μ Arae is the star's Bayer designation. HD 160691 is the entry in the Henry Draper Catalogue; the established convention for extrasolar planets is that the planets receive designations consisting of the star's name followed by lower-case Roman letters starting from "b", in order of discovery. This system was used by a team led by Krzysztof Goździewski. On the other hand, a team led by Francesco Pepe proposed a modification of the designation system, where the planets are designated in order of characterization. Since the parameters of the outermost planet were poorly constrained before the introduction of the 4-planet model of the system, this results in a different order of designations for the planets in the Mu Arae system.
Both systems agree on the designation of the 640-day planet as "b". The old system designates the 9-day planet as "d", the 310-day planet as "e" and the outer planet as "c". Since the International Astronomical Union has not defined an official system for designations of extrasolar planets, the issue of which convention is'correct' remains open, however subsequent scientific publications about this system appear to have adopted the Pepe et al. system, as has the system's entry in the Extrasolar Planets Encyclopaedia. In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars; the process involved public voting for the new names. In December 2015, the IAU announced the winning names were Cervantes for this star and Quijote, Dulcinea and Sancho, for its planets; the winning names were those submitted by the Planetario de Spain. Miguel de Cervantes Saavedra was a famous Spanish writer and author of El Ingenioso Hidalgo Don Quixote de la Mancha.
The planets are named after characters of that novel: Quijote was the lead character. In 2016, the IAU organized a Working Group on Star Names to catalog and standardize proper names for stars. In its first bulletin of July 2016, the WGSN explicitly recognized the names of exoplanets and their host stars approved by the Executive Committee Working Group Public Naming of Planets and Planetary Satellites, including the names of stars adopted during the 2015 NameExoWorlds campaign; this star is now so entered in the IAU Catalog of Star Names. According to measurements made by the Hipparcos astrometric satellite, Mu Arae exhibits a parallax of 64.47 milliarcseconds as the Earth moves around the Sun. When combined with the known distance from the Earth to the Sun, this means the star is located at a distance of 50.6 light years. Seen from Earth it is visible to the naked eye. Asteroseismic analysis of the star reveals it is 10% more massive than the Sun and older, at around 6.34 billion years. The radius of the star is 36% greater than that of the Sun and it is 90% more luminous.
The star contains twice the abundance of iron relative to hydrogen of the Sun and is therefore described as metal-rich. Mu Arae is more enriched than the Sun in the element helium. Mu Arae has a listed spectral type of G3IV–V; the G3 part means. The star may be entering the subgiant stage of its evolution as it starts to run out of hydrogen in its core; this is reflected in its uncertain luminosity class, between IV and V. In 2001, an extrasolar planet was announced by the Anglo-Australian Planet Search team, together with the planet orbiting Epsilon Reticuli; the planet, designated Mu Arae b, was thought to be in a eccentric orbit of around 743 days. The discovery was made by analysing variations in the star's radial velocity as a result of being pulled around by the planet's gravity. Further observations revealed the presence of a second object in the system, published in 2004. At the time, the parameters of this planet were poorly constrained and it was thought to be in an orbit of around 8.2 years with a high eccentricity.
In 2004, a small inner planet designated Mu Arae c was announced with a mass comparable to that of Uranus in a 9-day orbit. This was the first of the class of planets known as "hot Neptunes" to be discovered; the discovery was made by making high-precision radial velocity measurements with the High Accuracy Radial Velocity Planet Searcher spectrograph. In 2006, two teams, one led by Krzysztof Goździewski and the other by Francesco Pepe independently announced four-planet models for the radial velocity measurements of the star, with a new planet in a near-circular orbit lasting 311 days; the new model gives revised parameters for the known planets, with lower eccentricity orbits than in the previous model and including a more robust characterization of the orbit of Mu Arae e. The discovery of the fourth planet made Mu Arae the second known four-planet extrasolar system, after 55 Cancri; the Mu Arae system consists of an inner Uranus-mass planet in a tight 9-day orbit and three mas
International Astronomical Union
The International Astronomical Union is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy. Among other activities, it acts as the internationally recognized authority for assigning designations and names to celestial bodies and any surface features on them; the IAU is a member of the International Council for Science. Its main objective is to promote and safeguard the science of astronomy in all its aspects through international cooperation; the IAU maintains friendly relations with organizations that include amateur astronomers in their membership. The IAU has its head office on the second floor of the Institut d'Astrophysique de Paris in the 14th arrondissement of Paris. Working groups include the Working Group for Planetary System Nomenclature, which maintains the astronomical naming conventions and planetary nomenclature for planetary bodies, the Working Group on Star Names, which catalogs and standardizes proper names for stars.
The IAU is responsible for the system of astronomical telegrams which are produced and distributed on its behalf by the Central Bureau for Astronomical Telegrams. The Minor Planet Center operates under the IAU, is a "clearinghouse" for all non-planetary or non-moon bodies in the Solar System; the Working Group for Meteor Shower Nomenclature and the Meteor Data Center coordinate the nomenclature of meteor showers. The IAU was founded on 28 July 1919, at the Constitutive Assembly of the International Research Council held in Brussels, Belgium. Two subsidiaries of the IAU were created at this assembly: the International Time Commission seated at the International Time Bureau in Paris and the International Central Bureau of Astronomical Telegrams seated in Copenhagen, Denmark; the 7 initial member states were Belgium, France, Great Britain, Greece and the United States, soon to be followed by Italy and Mexico. The first executive committee consisted of Benjamin Baillaud, Alfred Fowler, four vice presidents: William Campbell, Frank Dyson, Georges Lecointe, Annibale Riccò.
Thirty-two Commissions were appointed at the Brussels meeting and focused on topics ranging from relativity to minor planets. The reports of these 32 Commissions formed the main substance of the first General Assembly, which took place in Rome, Italy, 2–10 May 1922. By the end of the first General Assembly, ten additional nations had joined the Union, bringing the total membership to 19 countries. Although the Union was formed eight months after the end of World War I, international collaboration in astronomy had been strong in the pre-war era; the first 50 years of the Union's history are well documented. Subsequent history is recorded in the form of reminiscences of past IAU Presidents and General Secretaries. Twelve of the fourteen past General Secretaries in the period 1964-2006 contributed their recollections of the Union's history in IAU Information Bulletin No. 100. Six past IAU Presidents in the period 1976–2003 contributed their recollections in IAU Information Bulletin No. 104. The IAU includes a total of 12,664 individual members who are professional astronomers from 96 countries worldwide.
83% of all individual members are male, while 17% are female, among them the union's former president, Mexican astronomer Silvia Torres-Peimbert. Membership includes 79 national members, professional astronomical communities representing their country's affiliation with the IAU. National members include the Australian Academy of Science, the Chinese Astronomical Society, the French Academy of Sciences, the Indian National Science Academy, the National Academies, the National Research Foundation of South Africa, the National Scientific and Technical Research Council, KACST, the Council of German Observatories, the Royal Astronomical Society, the Royal Astronomical Society of New Zealand, the Royal Swedish Academy of Sciences, the Russian Academy of Sciences, the Science Council of Japan, among many others; the sovereign body of the IAU is its General Assembly. The Assembly determines IAU policy, approves the Statutes and By-Laws of the Union and elects various committees; the right to vote on matters brought before the Assembly varies according to the type of business under discussion.
The Statutes consider such business to be divided into two categories: issues of a "primarily scientific nature", upon which voting is restricted to individual members, all other matters, upon which voting is restricted to the representatives of national members. On budget matters, votes are weighted according to the relative subscription levels of the national members. A second category vote requires a turnout of at least two-thirds of national members in order to be valid. An absolute majority is sufficient for approval in any vote, except for Statute revision which requires a two-thirds majority. An equality of votes is resolved by the vote of the President of the Union. Since 1922, the IAU General Assembly meets every three years, with the ex
Charles Scarborough
Sir Charles Scarborough or Scarburgh MP FRS FRCP was an English physician and mathematician. Scarborough was born in St. Martin's-in-the-Fields, Westminster, in 1615, to Edmund Scarburgh and his wife Hannah, was educated at St Paul's School and Caius College and Merton College, Oxford. While at Oxford he was a student of William Harvey, the two would become close friends. Scarborough was tutor to Christopher Wren, for a time his assistant. Following the Restoration in 1660, Scarborough was appointed physician to Charles II, who knighted him in 1669. During the reign of James II, Scarborough served as Member of Parliament for Camelford in Cornwall. Scarborough was an original fellow of the Royal Society and a fellow of the Royal College of Physicians, author of a treatise on anatomy, Syllabus Musculorum, used for many years as a textbook, a translator and commentator of the first six books of Euclid's Elements, he was the subject of a poem by Abraham Cowley, An Ode to Dr Scarborough. Scarborough died in London in 1694.
He was buried at Cranford, where there is a monument to him in the parish church erected by his widow. "Scarburgh, Charles". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900. Charles Scarborough at Find a Grave
Washington Double Star Catalog
The Washington Double Star Catalog, or WDS, is a catalog of double stars, maintained at the United States Naval Observatory. The catalog contains positions, proper motions and spectral types and has entries for 141,743 pairs of double stars; the catalog includes multiple stars. In general, a multiple star with n components will be represented by entries in the catalog for n-1 pairs of stars; the database used to construct the WDS originated at Lick Observatory, where it was used to construct the Index Catalog of Visual Double Stars, published in 1963. In 1965, under the initiative of Charles Worley, it was transferred to the Naval Observatory; the catalog has since been augmented by a large number of measurements from the Hipparcos and Tycho catalogues and results from speckle interferometry, as well as other sources. Aitken Double Star Catalogue Burnham Double Star Catalogue The WDS at the US Naval Observatory The Washington Double Star Catalog at VizieR StelleDoppie interface to the WDS
Pinyin
Hanyu Pinyin abbreviated to pinyin, is the official romanization system for Standard Chinese in mainland China and to some extent in Taiwan. It is used to teach Standard Mandarin Chinese, written using Chinese characters; the system includes four diacritics denoting tones. Pinyin without tone marks is used to spell Chinese names and words in languages written with the Latin alphabet, in certain computer input methods to enter Chinese characters; the pinyin system was developed in the 1950s by many linguists, including Zhou Youguang, based on earlier forms of romanizations of Chinese. It was published by revised several times; the International Organization for Standardization adopted pinyin as an international standard in 1982, was followed by the United Nations in 1986. The system was adopted as the official standard in Taiwan in 2009, where it is used for international events rather than for educational or computer-input purposes, but "some cities and organizations, notably in the south of Taiwan, did not accept this", so it remains one of several rival romanization systems in use.
The word Hànyǔ means'the spoken language of the Han people', while Pīnyīn means'spelled sounds'. In 1605, the Jesuit missionary Matteo Ricci published Xizi Qiji in Beijing; this was the first book to use the Roman alphabet to write the Chinese language. Twenty years another Jesuit in China, Nicolas Trigault, issued his Xi Ru Ermu Zi at Hangzhou. Neither book had much immediate impact on the way in which Chinese thought about their writing system, the romanizations they described were intended more for Westerners than for the Chinese. One of the earliest Chinese thinkers to relate Western alphabets to Chinese was late Ming to early Qing dynasty scholar-official, Fang Yizhi; the first late Qing reformer to propose that China adopt a system of spelling was Song Shu. A student of the great scholars Yu Yue and Zhang Taiyan, Song had been to Japan and observed the stunning effect of the kana syllabaries and Western learning there; this galvanized him into activity on a number of fronts, one of the most important being reform of the script.
While Song did not himself create a system for spelling Sinitic languages, his discussion proved fertile and led to a proliferation of schemes for phonetic scripts. The Wade–Giles system was produced by Thomas Wade in 1859, further improved by Herbert Giles in the Chinese–English Dictionary of 1892, it was popular and used in English-language publications outside China until 1979. In the early 1930s, Communist Party of China leaders trained in Moscow introduced a phonetic alphabet using Roman letters, developed in the Soviet Oriental Institute of Leningrad and was intended to improve literacy in the Russian Far East; this Sin Wenz or "New Writing" was much more linguistically sophisticated than earlier alphabets, but with the major exception that it did not indicate tones of Chinese. In 1940, several thousand members attended a Border Region Sin Wenz Society convention. Mao Zedong and Zhu De, head of the army, both contributed their calligraphy for the masthead of the Sin Wenz Society's new journal.
Outside the CCP, other prominent supporters included Sun Fo. Over thirty journals soon appeared written in Sin Wenz, plus large numbers of translations, some contemporary Chinese literature, a spectrum of textbooks. In 1940, the movement reached an apex when Mao's Border Region Government declared that the Sin Wenz had the same legal status as traditional characters in government and public documents. Many educators and political leaders looked forward to the day when they would be universally accepted and replace Chinese characters. Opposition arose, because the system was less well adapted to writing regional languages, therefore would require learning Mandarin. Sin Wenz fell into relative disuse during the following years. In 1943, the U. S. military engaged Yale University to develop a romanization of Mandarin Chinese for its pilots flying over China. The resulting system is close to pinyin, but does not use English letters in unfamiliar ways. Medial semivowels are written with y and w, apical vowels with r or z.
Accent marks are used to indicate tone. Pinyin was created by Chinese linguists, including Zhou Youguang, as part of a Chinese government project in the 1950s. Zhou is called "the father of pinyin," Zhou worked as a banker in New York when he decided to return to China to help rebuild the country after the establishment of the People's Republic of China in 1949, he became an economics professor in Shanghai, in 1955, when China's Ministry of Education created a Committee for the Reform of the Chinese Written Language, Premier Zhou Enlai assigned Zhou Youguang the task of developing a new romanization system, despite the fact that he was not a professional linguist. Hanyu Pinyin was based on several existing systems: Gwoyeu Romatzyh of 1928, Latinxua Sin Wenz of 1931, the diacritic markings from zhuyin. "I'm not the father of pinyin," Zhou said years later. It's a lo
Compact star
In astronomy, the term "compact star" refers collectively to white dwarfs, neutron stars, black holes. It would grow to include exotic stars. Most compact stars are the endpoints of stellar evolution, thus referred to as stellar remnants, the form of the remnant depending on the mass of the star when it formed. All of these objects have a high mass relative to their radius, giving them a high density; the term compact star is used when the exact nature of the star is not known, but evidence suggests that it is massive and has a small radius, thus implying one of the above-mentioned categories. A compact star, not a black hole may be called a degenerate star; the usual endpoint of stellar evolution is the formation of a compact star. Most stars will come to a point in their evolution when the outward radiation pressure from the nuclear fusions in its interior can no longer resist the ever-present gravitational forces; when this happens, the star collapses under its own weight and undergoes the process of stellar death.
For most stars, this will result in the formation of a dense and compact stellar remnant known as a compact star. Compact stars have no internal energy production, but will—with the exception of black holes—usually radiate for millions of years with excess heat left from the collapse itself. According to the most recent understanding, compact stars could form during the phase separations of the early Universe following the Big Bang. Primordial origins of known compact objects have not been determined with certainty. Although compact stars may radiate, thus cool off and lose energy, they do not depend on high temperatures to maintain their structure, as ordinary stars do. Barring external disturbances and proton decay, they can persist forever. Black holes are however believed to evaporate from Hawking radiation after trillions of years. According to our current standard models of physical cosmology, all stars will evolve into cool and dark compact stars, by the time the Universe enters the so-called degenerate era in a distant future.
The somewhat wider definition of compact objects includes smaller solid objects such as planets and comets. There is a remarkable variety of stars and other clumps of hot matter, but all matter in the Universe must end as some form of compact stellar or substellar object, according to the theory of thermodynamics; the stars called white or degenerate dwarfs are made up of degenerate matter. White dwarfs arise from the cores of main-sequence stars and are therefore hot when they are formed; as they cool they will redden and dim until they become dark black dwarfs. White dwarfs were observed in the 19th century, but the high densities and pressures they contain were not explained until the 1920s; the equation of state for degenerate matter is "soft", meaning that adding more mass will result in a smaller object. Continuing to add mass to what is now a white dwarf, the object shrinks and the central density becomes larger, with higher degenerate-electron energies; the star's radius has now shrunk to only a few thousand kilometers, the mass is approaching the theoretical upper limit of the mass of a white dwarf, the Chandrasekhar limit, about 1.4 times the mass of the Sun.
If we were to take matter from the center of our white dwarf and start to compress it, we would first see electrons forced to combine with nuclei, changing their protons to neutrons by inverse beta decay. The equilibrium would shift towards heavier, neutron-richer nuclei that are not stable at everyday densities; as the density increases, these nuclei become less well-bound. At a critical density of about 4×1014 kg/m3), called the neutron drip line, the atomic nucleus would tend to fall apart into protons and neutrons. We would reach a point where the matter is on the order of the density of an atomic nucleus. At this point the matter is chiefly free neutrons, with a small amount of electrons. In certain binary stars containing a white dwarf, mass is transferred from the companion star onto the white dwarf pushing it over the Chandrasekhar limit. Electrons react with protons to form neutrons and thus no longer supply the necessary pressure to resist gravity, causing the star to collapse. If the center of the star is composed of carbon and oxygen such a gravitational collapse will ignite runaway fusion of the carbon and oxygen, resulting in a Type Ia supernova that blows apart the star before the collapse can become irreversible.
If the center is composed of magnesium or heavier elements, the collapse continues. As the density further increases, the remaining electrons react with the protons to form more neutrons; the collapse continues. A new equilibrium is possible after the star shrinks by three orders of magnitude, to a radius between 10 and 20 km; this is a neutron star. Although the first neutron star was not observed until 1967 when the first radio pulsar was discovered, neutron stars were proposed by Baade and Zwicky in 1933, only one year after the neutron was discovered in 1932, they realized that because neutron stars are so dense, the collapse of an ordinary star to a neutron star would liberate a large amount of gravitational potential energy, providing a possible explanation for supernovae. This is the explanation for supernovae of types Ib, Ic, II; such supernovae occur when the iron core of a massive star exceeds the Chandrasekhar limit and collapses to a neutron star. Li
