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γ Ceti
Gamma Ceti (γ Ceti, abbreviated Gamma Cet, γ Cet) is a triple star system in the equatorial constellation of Cetus. It has a combined apparent visual magnitude of 3.47. Based upon parallax measurements, this star is located at a distance of about 80 light-years (24.4 parsecs) from the Sun. The three components are designated Gamma Ceti A (officially named Kaffaljidhma , the traditional name for the entire system), B and C. Nomenclature ''γ Ceti'' ( Latinised to ''Gamma Ceti'') is the system's Bayer designation. The designations of the three components as ''Gamma Ceti A'', ''B'' and ''C'' derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). The close pair AB is also designated HIP 12706, HD 16970, and HR 804. The system of A, B, and C is collectively designated GJ 106.1 in the Gliese Catalogue of Nearby Stars. Gamma Ceti bore the tradition ... [...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] |
International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels, Belgium 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. the Union had 85 national members and 12,734 individual members, spanning 90 countries and territories. 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] |
Alpha Ceti
Alpha Ceti (α Ceti, abbreviated Alpha Cet, α Cet), officially named Menkar , is the second-brightest star in the constellation of Cetus. It is a cool luminous red giant estimated to be about 250 light years away based on parallax. Nomenclature ''Alpha Ceti'' is the star's Bayer designation. It has the traditional name Menkar, deriving from the Arabic word منخر ''manħar'' "nostril" (of Cetus). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) 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; which included ''Menkar'' for this star. This star, along with γ Cet (Kaffaljidhma), δ Cet, λ Cet (also Menkar), μ Cet, ξ1 Cet and ξ2 Cet were ''Al Kaff al Jidhmah'', "the Part of a Hand". In Chinese, (), meaning '' Circular Celestial Granary'', refers to an asterism consisting of α Ceti, κ1 Ceti, λ C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mu Ceti
Mu Ceti (μ Ceti) is a binary star in the constellation Cetus, the whale, close to Pisces. The combined apparent magnitude of the system is +4.27, making it visible as a faint star from skies with low or no luminous pollution. Based upon parallax measurements taken by the Gaia spacecraft, it is located 87 light-years away. The location of Mu Ceti next to the ecliptic make it succeptible to lunar occultations. Nomenclature Mu Ceti is the system's Bayer designation. It has no official proper name. In Chinese, (), meaning '' Circular Celestial Granary'', refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for Mu Ceti itself is "the Fourth Star of Circular Celestial Granary". [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Ceti
Delta Ceti, Latinisation of names, Latinized from δ Ceti, is a single, blue-white hued star in the equatorial constellation of Cetus (constellation), Cetus. The star's apparent visual magnitude of +4.06 means it is near to the cusp of the faintest third of the stars that are visible the ideally-placed naked eye. It is north of the celestial equator compared to the celestial north pole's . The star is positioned about boxing the compass, WNW of the spiral galaxy Messier 77, M77, but which at apparent magnitude 9.6 needs magnification to be made out and has an angular diameter, apparent size of only by . Based upon an annual stellar parallax, parallax shift of as seen from Earth, it is around from the Sun. Motion relative to our system's trajectory includes a highly parting vector: with a net radial velocity of about . It moves minutely across the celestial sphere – yet just over four times more in right ascension than in declination. This is a Beta Cephei var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xi2 Ceti
Xi2 Ceti, Latinized from ξ2 Ceti, is a star located in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of +4.3. This star is located at a distance of approximately 197 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 12 km/s. It made its closest approach some 2.7 million years ago at a distance of around . Xi2 Ceti is a spectrophotometric standard star. It displays a stellar classification of B9.5III, which suggests it has exhausted its core hydrogen, evolved away from the main sequence, and expanded to become a giant star, although still only 127 million years old. It has 2.45 times the mass and 2.6 times the radius of the Sun. In Chinese, (), meaning '' Circular Celestial Granary'', refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xi1 Ceti
Xi1 Ceti , Latinized from ξ1 Ceti, is a binary star system located in the equatorial constellation of Cetus. It is visible to the naked eye with a combined apparent visual magnitude of +4.36. The distance to this system is approximately 340 light years based on parallax measurements, and it is drifting closer to the Sun with a radial velocity of −4 km/s. The proximity of the star to the ecliptic means it is subject to lunar occultations. The spectroscopic binary nature of Xi1 Ceti was discovered in 1901 by William Wallace Campbell using the Mills spectrograph at the Lick Observatory. The pair have a circular orbit with a period of 4.5 years and a separation of . It is a suspected eclipsing binary with an amplitude of 0.03 in magnitude, which would suggest the orbital plane has a high inclination. The primary, designated component A, is a mild barium giant star with a stellar classification of . Morgan and Keenan in 1973 had classified it as a brigh ... [...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] |
Gliese Catalogue Of Nearby Stars
The ''Gliese Catalogue of Nearby Stars'' (, English ) is a star catalogue listing stars located within 25 parsecs (82 ly) of the Sun. First edition and supplements In 1957, German astronomer Wilhelm Gliese published his first star catalogue of 915 known stars within of Earth, listing their known properties and ordered geographically by right ascension. Stars in the first catalogue are designated by coding ''GL NNN'', the N representing the consecutive integer number based on this order. Gliese published an update as the ''Catalogue of Nearby Stars'' in 1969, all known stars to , which catalogued 1,529 stars, encoded as ''Gl NNN.NA'' (prefix Gl and the entries of twelve years before gained a .0 affix; the more than 500 additional stars were recorded using interspersed 0.1, 0.2 etc. numbering). This list therefore numbered from 1.0 to 915.0 as no stars were entered after 915.0. and retained a strict right ascension order. A Supplement published in 1970 by Richard van ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bright Star Catalogue
The Bright Star Catalogue, also known as the Yale Catalogue of Bright Stars, Yale Bright Star Catalogue, or just YBS, is a star catalogue that lists all stars of stellar magnitude 6.5 or brighter, which is roughly every star visible to the naked eye from Earth. The catalog lists 9,110 objects, of which 9,095 are stars, 11 are novae or supernovae (which were "bright stars" only at the time when they were at their peak), and four are non-stellar objects which are the globular clusters 47 Tucanae (designated HR 95) and NGC 2808 (HR 3671), and the open clusters NGC 2281 (HR 2496) and Messier 67 (HR 3515). The catalogue is fixed in number of entries, but its data is maintained, and it is appended with a comments section about the objects that has been steadily enhanced. The abbreviation for the catalog as a whole is BS or YBS but all citations of stars it indexes use HR before the catalog number, a homage to the catalog's direct predecessor, published ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Draper Catalogue
The ''Henry Draper Catalogue'' (HD) is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the ''Henry Draper Extension'' (HDE), published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the ''Henry Draper Extension Charts'' (HDEC), published from 1937 to 1949 in the form of charts, which gave classifications for 86,933 more stars. In all, 359,083 stars were classified as of August 2017. The HD catalogue is named after Henry Draper, an amateur astronomer, and covers the entire sky almost completely down to an apparent photographic magnitude of about 9; the extensions added fainter stars in certain areas of the sky. The construction of the ''Henry Draper Catalogue'' was part of a pioneering effort to classify stellar spectra, and its catalogue numbers are commonly used as a way of identifying stars. History The origin of the ''Henry Draper Catalogue'' d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hipparcos
''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions and distances of celestial objects on the sky. This permitted the first high-precision measurements of the intrinsic brightnesses, proper motions, and parallaxes of stars, enabling better calculations of their distance and tangential velocity. When combined with radial velocity measurements from spectroscopy, astrophysicists were able to finally measure all six quantities needed to determine the motion of stars. The resulting ''Hipparcos Catalogue'', a high-precision catalogue of more than 118,200 stars, was published in 1997. The lower-precision ''Tycho Catalogue'' of more than a million stars was published at the same time, while the enhanced Tycho-2 Catalogue of 2.5 million stars was published in 2000. ''Hipparcos'' follow-up mission, '' Gaia'', was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
