EntityQ1666400· pop 20· linked from 1,176 articlesInternational Celestial Reference SystemSign in to savecelestial reference system using reference celestial sources observed at radio wavelengthsConnectionsvery-long-baseline interferometryEntityepochEntityHipparcosEntitybarycenterEntityInternational Earth Rotation and Reference Systems ServiceEntityCatalogues of Fundamental StarsEntityminute and second of arcEntityInternational Terrestrial Reference SystemEntityastronomyEntitySolar SystemEntitygravityEntityInternational Standard Book NumberEntitygeneral relativityEntityWayback MachineEntityastronomical objectEntitydigital object identifierEntityInternational Standard Serial NumberEntityInternational Astronomical UnionEntityquasarEntityrotationEntityCategoriesAstrometryAstronomical coordinate systemsFrames of reference