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Sigma Hydrae
Sigma Hydrae (σ Hydrae, abbreviated Sigma Hya, σ Hya), also named Minchir , is a solitary star in the equatorial constellation of Hydra. It is visible to the naked eye with an apparent visual magnitude of 4.48. The estimated distance to this star from the Sun, based upon an annual parallax shift of 8.75 mas, is around 370 light-years. At that distance, the visual magnitude of the star is diminished by an interstellar extinction factor of 0.16, due to intervening dust. Nomenclature ''σ Hydrae'' ( Latinised to ''Sigma Hydrae'') is the system's Bayer designation. It bore the traditional name ''Minchir'', appearing as ''Minchir es-schudscha'' in Bode's large star atlas, ''Uranographia''. The name which derived from the Arabic appelationمنخر الشجاع ''minkhar ash-shujāʽ'' "the nostril brave one" (the hydra) for this star. The name is erroneously spelt as ''Al Minliar al Shuja'' in the Yale ''Bright Star Catalogue''. In 2016, the IAU organized a Wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Latinisation Of Names
Latinisation (or Latinization) of names, also known as onomastic Latinisation (or onomastic Latinization), is the practice of rendering a ''non''-Latin name in a Neo-Latin, modern Latin style. It is commonly found with historical proper names, including personal names and toponyms, and in the standard binomial nomenclature of the life sciences. It goes further than romanisation, which is the transliteration of a word to the Latin alphabet from another script (e.g. Cyrillic). For authors writing in Latin, this change allows the name to function grammatically in a sentence through declension. In a scientific context, the main purpose of Latinisation may be to produce a name which is internationally consistent. Latinisation may be carried out by: * transforming the name into Latin sounds (e.g. for ), or * adding Latinate suffixes to the end of a name (e.g. for ''Heinrich Meibom (doctor), Meibom),'' or * translating a name with a specific meaning into Latin (e.g. for Italian ; b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willow (Chinese Constellation)
The Willow mansion (柳宿, pinyin: Liǔ Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the southern mansions of the Vermilion Bird The Vermilion Bird ( zh, c=朱雀, p=Zhūquè) is one of the Four Symbols of the Chinese constellations. According to Wuxing (Chinese philosophy), Wu Xing, the Taoism, Taoist five elemental system, it represents the Fire (Wu Xing), Fire element, .... Asterisms References {{DEFAULTSORT:Willow (Chinese Constellation) Chinese constellations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Language
Chinese ( or ) is a group of languages spoken natively by the ethnic Han Chinese majority and List of ethnic groups in China, many minority ethnic groups in China, as well as by various communities of the Chinese diaspora. Approximately 1.39 billion people, or 17% of the global population, speak a variety of Chinese as their first language. Chinese languages form the Sinitic languages, Sinitic branch of the Sino-Tibetan language family. The spoken varieties of Chinese are usually considered by native speakers to be dialects of a single language. However, their lack of mutual intelligibility means they are sometimes considered to be separate languages in a Language family, family. Investigation of the historical relationships among the varieties of Chinese is ongoing. Currently, most classifications posit 7 to 13 main regional groups based on phonetic developments from Middle Chinese, of which the most spoken by far is Mandarin Chinese, Mandarin with 66%, or around 800&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States's civil list of government space agencies, space program, aeronautics research and outer space, space research. National Aeronautics and Space Act, Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion (spacecraft), Orion spacecraft and the Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rho Hydrae
Rho Hydrae, equally written ρ Hydrae, is a binary star in the equatorial constellation of Hydra. It is visible to the naked eye with an apparent visual magnitude of 4.34. The distance to this system, based upon an annual parallax shift of 9.21 mas, is about 354 light years. At that distance, the visual magnitude is diminished by an interstellar extinction of 0.06 magnitudes, due to intervening dust. The primary component is an A-type main sequence star with a stellar classification of A0 Vn. It has around double the radius of the Sun and 3.2 times the Sun's mass. Rho Hydrae is around 350 million years old and has a high rate of spin, with a projected rotational velocity of 128 km/s. It radiates 242 times the solar luminosity from its outer atmosphere at an effective temperature of 9,795 K. The companion is a magnitude 11.9 star at an angular separation of 12.1 arc seconds along a position angle of 146°, as of 2000. Name and etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Hydrae
Eta Hydrae (η Hydrae) is a star in the equatorial constellation of Hydra (constellation), Hydra. With an apparent visual magnitude of 4.3, it is visible to the naked eye. However, it is the faintest of the five stars that form the "head" of the hydra. Based upon an annual stellar parallax, parallax shift of 5.56 milliarcsecond, mas, it is located roughly 590 light years from the Sun. This is a B-type main sequence star with a stellar classification of B3V. It has been classified as a candidate Beta Cephei variable with a period of 2.2 days, although this designation was rejected by Stankov and Handler (2005). The stellar spectrum, spectrum shows a slight underabundance of carbon, compared to the Sun. The star is around 32 million years old and is spinning with a projected rotational velocity of 101 km/s. It has an estimated seven times the solar mass, mass of the Sun and nearly four times the solar radius, Sun's radius. Eta Hydrae radiates 2,680 times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta Hydrae
Zeta Hydrae (ζ Hya, ζ Hydrae) is a solitary star in the equatorial constellation of Hydra. This is a generally faint constellation, so, at an apparent visual magnitude of +3.10, this is the third-brightest member after Alphard and Gamma Hydrae. Distance The distance to this star has been measured using the parallax technique, yielding a value of roughly . At this distance, the visual magnitude of the star is diminished by 0.03 as a result of extinction from intervening gas and dust. Delta Hydrae is about from Zeta Hydrae and may be a largely co-moving object. The star has one of the lower-error margin readings among those of the Gaia spacecraft which computes a parallax of 20.7182 ± 0.3925 mas and, if correct, a distance of 157 ± 3 light years. Characteristics With a stellar classification of G9 II-III, this is an evolved giant star that is radiating 174 times the luminosity of the Sun from its outer envelope at an effective temperature of around 5,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Hydrae
Epsilon Hydrae (ε Hydrae, abbreviated Epsilon Hya, ε Hya) is a multiple star system of a combined third magnitude in the constellation of Hydra. Based upon parallax measurements obtained during the Hipparcos mission, it is located roughly distant from the Sun. The system consists of a binary pair designated Epsilon Hydrae AB, whose two components are themselves designated Epsilon Hydrae A (formally named Ashlesha ) and B, orbited by a spectroscopic binary designated Epsilon Hydrae C. A possible fourth component, designated Epsilon Hydrae D, shares a common proper motion with the other components and thus is most likely a gravitationally-bound member of the system. Nomenclature ''ε Hydrae'' ( Latinised to ''Epsilon Hydrae'') is the system's Bayer designation. The designations of the three constituents as ''Epsilon Hydrae AB'', ''C'' and ''D'', and those of ''AB's'' components - ''Epsilon Hydrae A'' and ''B'' - derive from the convention used by the Washington ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Hydrae
Delta Hydrae, Latinized from δ Hydrae, is a triple star in the equatorial constellation of Hydra. It is visible to the naked eye with an apparent visual magnitude of 4.146. Based upon an annual parallax shift of 20.34 mas, it is located about 160 light years distant. Characteristics This is a hierarchical triple system. δ Hydrae Aa and δ Hydrae Ab form a close binary system with an orbital separation of 0.9 astronomical units, taking about 200 days to complete an orbit. The outer companion, δ Hydrae B, has an angular separation of from the Aa–Ab pair, along a position angle of , as of 2003. At the system's distance, this separation translates in a physical projected separation of 147 AU. The brighter component, δ Hydrae Aa, is an A-type main sequence star with a stellar classification of A1 Vnn. It is spinning rapidly with a projected rotational velocity of 285 km/s. This is giving the star an oblate shape with an equatorial bul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IAU 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yale University
Yale University is a Private university, private Ivy League research university in New Haven, Connecticut, United States. Founded in 1701, Yale is the List of Colonial Colleges, third-oldest institution of higher education in the United States, and one of the nine colonial colleges chartered before the American Revolution. Yale was established as the Collegiate School in 1701 by Congregationalism in the United States, Congregationalist clergy of the Connecticut Colony. Originally restricted to instructing ministers in theology and sacred languages, the school's curriculum expanded, incorporating humanities and sciences by the time of the American Revolution. In the 19th century, the college expanded into graduate and professional instruction, awarding the first Doctor of Philosophy, PhD in the United States in 1861 and organizing as a university in 1887. Yale's faculty and student populations grew rapidly after 1890 due to the expansion of the physical campus and its scientif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
