19 relations: Astrometry, Astronomical radio source, Astronomy, Barycenter, Barycentric celestial reference system, Celestial coordinate system, Epoch (astronomy), Equatorial coordinate system, Equinox, Hipparcos, International Astronomical Union, International Celestial Reference Frame, International Earth Rotation and Reference Systems Service, International Terrestrial Reference System, Minute and second of arc, Quasar, Right ascension, Solar System, Very-long-baseline interferometry.
Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies.
Astronomical radio sources are objects in outer space that emit strong radio waves.
Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.
The barycenter (or barycentre; from the Ancient Greek βαρύς heavy + κέντρον centre) is the center of mass of two or more bodies that are orbiting each other, which is the point around which they both orbit.
The Barycentric celestial reference system (BCRS) is a coordinate system used in astrometry to specify the location and motions of astronomical objects.
In astronomy, a celestial coordinate system is a system for specifying positions of celestial objects: satellites, planets, stars, galaxies, and so on.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of celestial objects.
An equinox is commonly regarded as the moment the plane (extended indefinitely in all directions) of Earth's equator passes through the center of the Sun, which occurs twice each year, around 20 March and 22-23 September.
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.
The International Astronomical Union (IAU; Union astronomique internationale, UAI) is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy.
In astrometry, an International Celestial Reference Frame (ICRF) is a realization of the International Celestial Reference System (ICRS) using reference celestial sources observed at radio wavelengths.
The International Earth Rotation and Reference Systems Service (IERS), formerly the International Earth Rotation Service, is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Parameter (EOP) and International Celestial Reference System (ICRS) groups.
The International Terrestrial Reference System (ITRS) describes procedures for creating reference frames suitable for use with measurements on or near the Earth's surface.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
A quasar (also known as a QSO or quasi-stellar object) is an extremely luminous active galactic nucleus (AGN).
Right ascension (abbreviated RA; symbol) is the angular distance measured only eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point above the earth in question.
The Solar SystemCapitalization of the name varies.
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy.