Of the sun or other celestial object: appearing or emerging above the horizon. Hence: (of the morning or the day) having just begun, new. Also in…

Of or belonging to ascension. ascensional difference in Astronomy: the difference between the right and oblique ascension of the sun or a star.

Astronomy. Of or relating to the rising of a celestial object. Usually in ortive amplitude: the angular distance of an object at its rising…