- right ascension, RA, celestial longitude - (astronomy) the angular distance eastward along the celestial equator from the vernal equinox to the intersection of the hour circle that passes through the body; expressed in hours and minutes and second; used with declination to specify positions on the celestial sphere; "one hour of right ascension equals fifteen degrees"
--1 is a kind of angular distance
- right ascension - an arc of the celestial equator eastward from the vernal equinox
--2 is a kind of celestial equator, equinoctial circle, equinoctial line, equinoctial