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Kaus Media
Delta Sagittarii (δ Sagittarii, abbreviated Delta Sgr, δ Sgr), formally named Kaus Media , is a double star in the southern zodiac constellation of Sagittarius. The apparent visual magnitude of this star is +2.70, making it easily visible to the naked eye. Parallax measurements place the distance at roughly from the Sun. Properties Eggleton and Tokovinin (2008) list Delta Sagittarii as a binary star system consisting of an evolved K-type giant star with a stellar classification of K3 III, and a white dwarf companion. The giant is a weak barium star, most likely having had its surface abundance of s-process elements enhanced through mass transfer from its orbiting companion. It has an estimated 3.21 times the mass of the Sun and is about 260million years old. Delta Sagittarii has three dim visual companions: * a 14th magnitude star at a separation of 26 arcseconds, * a 15th magnitude star at a separation of 40 arcseconds, and * a 13th mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, 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 Astronomical object, celestial body, as they are subject to Perturbation (astronomy), 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 Perihelion and aphelion, 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 bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observatoire Royal De Belgique
The Royal Observatory of Belgium (french: link=no, Observatoire Royal de Belgique, nl, Koninklijke Sterrenwacht van België), has been situated in the Uccle municipality of Brussels (Belgium) since 1890. It was first established in Saint-Josse-ten-Noode in 1826 by William I under the impulse of Adolphe Quetelet. It was home to a diameter aperture Zeiss reflector in the first half of the 20th century, one of the largest telescopes in the world at the time. It owns a variety of other astronomical instruments, such as astrographs, as well as a range of seismograph equipment (for detecting earthquakes). Its main activities are: * Reference systems and geodynamics; * Astrometry and dynamics of celestial bodies; * Astrophysics; * Solar physics. The asteroid 1276 Ucclia is named in honour of the city and the observatory and 16908 Groeselenberg is named for the hill the observatory is located on. History 19th century Adolphe Quetelet first petitioned the government of the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Sagittarii
Eta Sagittarii (Eta Sgr, η Sagittarii, η Sgr) is a binary star system in the southern zodiac constellation of Sagittarius. Based upon parallax measurements, it is located at a distance of from Earth. It was formerly known as Beta Telescopii (β Tel). In India, where part of the constellation of Sagittarius represents an Elephant, this star forms the creature's tail. The primary component, η Sagittarii A, is a red giant star with a stellar classification of M2 III. It is an evolved star that is currently at a stage called the asymptotic giant branch, having exhausted both the hydrogen and the helium at its core. This star is classified as an oxygen-rich irregular variable, as it undergoes small magnitude fluctuations between +3.08 and 3.12. The measured angular diameter of this star is . At the estimated distance of Eta Draconis, this yields a physical size of about 57 times the radius of the Sun. The companion, η Sagittarii B, was f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Sagittarii
Epsilon Sagittarii ( Latinised from ε Sagittarii, abbreviated Epsilon Sgr, ε Sgr), formally named Kaus Australis , is a binary star system in the southern zodiac constellation of Sagittarius. The apparent visual magnitude of +1.85 makes it the brightest object in Sagittarius. Based upon parallax measurements, this star is around from the Sun. Stellar system The primary star, ε Sagittarii A, of this binary star system has a stellar classification of B9.5 III, with the luminosity class of III suggesting this is an evolved giant star that has exhausted the supply of hydrogen at its core. The interferometry-measured angular diameter of this star, after correcting for limb darkening, is , which, at its estimated distance, equates to a physical radius of about 6.8 times the radius of the Sun. This is a close match to the empirically-determined value of 6.9 solar radii. It has about 3.5 times the mass of the Sun and is radiating around 363 time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma2 Sagittarii
Gamma² Sagittarii (γ² Sagittarii, abbreviated Gamma² Sgr, γ² Sgr), formally named Alnasl , is a 3rd-magnitude star in the zodiac constellation of Sagittarius. The location of this star is in the handle of the Bow of Sagittarius the Centaur. Based on parallax measurements obtained during the Hipparcos mission, it is approximately from the Sun. It has an apparent visual magnitude of +2.98, making it the seventh-brightest star in the constellation. It forms part of a double star along with a fainter optical companion designated Gamma¹ Sagittarii located about 50 arcminutes north of this star. The latter is a magnitude 4.7 Cepheid variable star that also has the variable star designation W Sagittarii. Nomenclature ''γ² Sagittarii'' ( Latinised to ''Gamma² Sagittarii'') is the star's Bayer designation. It bore the traditional names ''Alnasl'' (alternatively ''Nasl'', ''El Nasl'', "al Nasl"), ''Nushaba'' (''Nash'') and ''Awal al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winnowing Basket (Chinese Constellation)
The Winnowing Basket mansion (箕宿, pinyin Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Chinese, Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally writte ...: Jī Xiù) is one of the Twenty-Eight Mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon. Asterisms References {{DEFAULTSORT:Winnowing Basket (Chinese Constellation) Chinese constellations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting original research in relevant fields. Despite the name, the journal is no longer monthly, nor does it carry the notices of the Royal Astronomical Society. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second volume, after the Astronomical Society of London became the Royal Astronomical Society (RAS). Until 1960 it carried the monthly notices of the RAS, at which time these were transferred to the newly established ''Quarterly Journal of the Royal Astronomical Society'' (1960–1996) and then to its successor journal ''Astronomy & Geophysics'' (since 1997). Until 1965, MNRAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warida
Warida or Al Warida is an asterism of the Arabs. In the star catalogue of Al Achsasi al Mouakket, four stars are mentioned as belonging to it: Gamma Sagittarii, Delta Sagittarii, Epsilon Sagittarii and Eta Sagittarii. The name is short for Arabic النعامة الواردة ''Al Naʽāma al Wārida'', meaning "the ostrich Ostriches are large flightless birds of the genus ''Struthio'' in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, and kiwis. There are ... going down to the water". This ostrich was thought of as going down to the river (the Milky Way) to drink, and another ostrich (σ, φ, τ, and ζ Sagittarii, ''al Sadira'') was thought of as coming back up. References Sagittarius (constellation) Asterisms (astronomy) {{star-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Al Achsasi Al Mouakket
Muḥammad al-Akhṣāṣī al-Muwaqqit ( ar, محمد الاخصاصي الموقت) was an Egyptian astronomer whose and catalogue of stars, ('Pearls of brilliance upon the solar operations'), was written at Cairo about 1650. Al-Akhsasi was a shaykh, a learned elder, of the Grand Mosque of the university of Cairo, where his name ''al- Muwaqqit'' reflected his position regulating the times and hours at the mosque. His name Akhsasi connects him in origin to a village in the Faiyum, southwest of Cairo. No copies of his book were known to Western astronomers or historians of science The history of science covers the development of science from ancient times to the present. It encompasses all three major branches of science: natural, social, and formal. Science's earliest roots can be traced to Ancient Egypt and Mesop ... until 1895;Knobel 1895. thus he did not appear in the standard French and English bibliographies and library catalogues of the 19th century. Notes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
