right ascension

/raɪt əˌsɛntʃən/

Other forms: right ascensions

Definitions of right ascension

1. noun

   (astronomy) the equatorial coordinate specifying the angle, measured eastward along the celestial equator, from the vernal equinox to the intersection of the hour circle that passes through an object in the sky; usually expressed in hours and minutes and seconds; used with declination to specify positions on the celestial sphere
   “one hour of right ascension equals fifteen degrees”

   synonyms: RA, celestial longitude

   type of:

   angular distance

   the angular separation between two objects as perceived by an observer