Meaning of right ascension

right' ascen'sion

Pronunciation: [key]
— Astron. Astron.
  1. the arc of the celestial equator measured eastward from the vernal equinox to the foot of the great circle passing through the celestial poles and a given point on the celestial sphere, expressed in degrees or hours.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.