Topic summary
Barycentric Celestial Reference System

Extracted from the Wikipedia article Barycentric and geocentric celestial reference systems.
The barycentric celestial reference system (BCRS) is a coordinate system used in astrometry to specify the location and motions of astronomical objects. Its center of coordinates as the center of mass of the entire Solar System, its barycenter. It was created in 2000 by the International Astronomical Union (IAU) to be the global standard reference system for objects located outside the gravitational vicinity of Earth: planets, moons, and other Solar System bodies, stars and other objects in the Milky Way galaxy, and extra-galactic objects.