International Celestial Reference System and its realizations information
Current standard celestial reference system and frame
The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU). Its origin is at the barycenter of the Solar System, with axes that are intended to "show no global rotation with respect to a set of distant extragalactic objects".[1][2] This fixed reference system differs from previous reference systems, which had been based on Catalogues of Fundamental Stars that had published the positions of stars based on direct "observations of [their] equatorial coordinates, right ascension and declination"[3] and had adopted as "privileged axes ... the mean equator and the dynamical equinox" at a particular date and time.[4]
The International Celestial Reference Frame (ICRF) is a realization of the International Celestial Reference System using reference celestial sources observed at radio wavelengths. In the context of the ICRS, a reference frame (RF) is the physical realization of a reference system, i.e., the reference frame is the set of numerical coordinates of the reference sources, derived using the procedures spelled out by the ICRS.[5]
More specifically, the ICRF is an inertial barycentric reference frame whose axes are defined by the measured positions of extragalactic sources (mainly quasars) observed using very-long-baseline interferometry while the Gaia-CRF is an inertial barycentric reference frame defined by optically measured positions of extragalactic sources by the Gaia satellite and whose axes are rotated to conform to the ICRF. Although general relativity implies that there are no true inertial frames around gravitating bodies, these reference frames are important because they do not exhibit any measurable angular rotation since the extragalactic sources used to define the ICRF and the Gaia-CRF are so far away. The ICRF and the Gaia-CRF are now the standard reference frames used to define the positions of astronomical objects.[6]
^Cite error: The named reference IAU91 was invoked but never defined (see the help page).
^Cite error: The named reference IAU97 was invoked but never defined (see the help page).
^Walter, Hans G.; Sovers, Oscar J. (2000), Astrometry of Fundamental Catalogues: The Evolution from Optical to Radio Reference Frames, Berlin: Springer, p. 1, ISBN 9783540674368
^Arias, E.F.; Charlot, P.; Feissel, M.; Lestrade, J.-F. (1995), "The Extragalactic Reference System of the International Earth Rotation Service, ICRS", Astronomy and Astrophysics, 303: 604–608, Bibcode:1995A&A...303..604A
^"International Celestial Reference System (ICRS)". aa.usno.navy.mil. US Naval Observatory. Retrieved 23 June 2022.
^Cite error: The named reference IAU21 was invoked but never defined (see the help page).
and 25 Related for: International Celestial Reference System and its realizations information
global time andreference frame standards, notably through its Earth Orientation Parameter (EOP) andInternationalCelestialReferenceSystem (ICRS) groups...
needed] Month Lunar year Timekeeping on Mars InternationalCelestialReferenceSystemanditsrealizations Nautical time Sidereal time Ramirez-Simon, Diana...
astronomical objects InternationalCelestialReferenceSystemandItsRealizations, the current IAU approved reference frames in radio and optical wavelengths...
In physics and astronomy, a frame of reference (or reference frame) is an abstract coordinate system whose origin, orientation, and scale are specified...
in reference to the status of the Emperor of China as the Son of Heaven in the Sinosphere. Accordingly, in the 19th century, the name "Celestial" was...
versions, the ideal International Terrestrial ReferenceSystem (ITRS) anditsrealization, the International Terrestrial Reference Frame (ITRF). A current...
mass. The 1980 Geodetic ReferenceSystem (GRS 80), adopted at the XVII General Assembly of the International Union of Geodesy and Geophysics (IUGG), posited...
increasingly from the late 1950s as secondary realizations of ephemeris time (ET). These secondary realizations improved on the original ET standard by the...
quantity indicated was not identical with any of the other realizations of ET such as ET0, ET1), and that while A.1 gave "certainly a closer approximation...
waymarking, and other kinds of location based mobile games such as Pokémon Go. Reference frames: realizationand densification of the terrestrial reference frames...
Religious, and Scientific Perspectives. Routledge. pp. 37–52. Rochberg, Francesca (2010). In the Path of the Moon: Babylonian Celestial Divination andIts Legacy...
Retrieved 3 August 2008. International Earth Rotation andReferenceSystems Service (IERS) Working Group (2004). "General Definitions and Numerical Standards"...
The second (symbol: s) is the unit of time in the InternationalSystem of Units (SI), historically defined as 1⁄86400 of a day – this factor derived from...
three largest asteroids, the Moon–Earth mass ratio and the Astronomical Unit". Celestial Mechanics and Dynamical Astronomy. 103 (4): 365–372. Bibcode:2009CeMDA...
divine year. This is as per the following belief system: The gods are believed to reside in the north celestial sphere. Due to the axial tilt of the earth,...
orbital city or orbital colony) around the Earth or any other celestial body, as well as cyclers and interstellar arks, as generation ships or world ships. Space...
Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites". Celestial Mechanics and Dynamical Astronomy. 63 (2): 127–148...
Meteoroskopeion, i.e., a building showing celestial phenomena and the time. It had a pointer for the time and some automations similar to the Archimedes...
Shingon Buddhism and Nepalese Newar Buddhism. Although Southern Esoteric Buddhism does not directly reference the tantras, its practices and ideas parallel...
universe and the laws that govern celestial motion. Ptolemy goes beyond the mathematical models of the Almagest to present a physical realization of the...
center of the Northern Celestial Masters located in the Zhongnan mountains. This work is widely cited and commented upon and describes meditation in...
Kopejkin, S. M. (1990). "Relativistic time scales in the solar system". Celestial Mechanics and Dynamical Astronomy. 48 (1): 23–44. doi:10.1007/BF00050674...