EntityQ3380435· pop 17· linked from 8 articlesHour circleSign in to savePart of celestial coordinate systemConnectionsepochEntityastronomyEntitystarEntityplanetEntitylongitudeEntityastronomical objectEntityequinoxEntityglobeEntityradianEntitycelestial sphereEntitydeclinationEntityright ascensionEntitycelestial equatorEntityright angleEntitygreat circleEntityEarth's rotationEntityperpendicularityEntitycenter of massEntitycelestial poleEntityDelft University of TechnologyEntityCategoriesAstronomical coordinate systemsCircles