An Etymological Dictionary of Astronomy and Astrophysics

A coordinate in the → equatorial system measured from the → vernal equinox eastward to the point where the object → hour circle intersects the → celestial equator. Right ascension (symbol α) is expressed in hours, minutes, and seconds. See also: → declination.

Etymology (EN): → right; ascension, M.E. ascencioun, from O.Fr., from L. ascendere “to climb up,” from → ad- “to” + scandere “to climb.”

Etymology (PE): Râst, → right; afrâz present stem of afrâzidan, afrâštan “to raise, exalt, extole,” from Mid.Pers. abrâstan, abrâz- “to lift, raise,”
from ab-, from O.Pers./Av. abiy-/aiwi- “to, upon, against;” cf. Skt. abhi-, Gk. amphi- + râst “straight, direct, true;”
from O.Pers. rāsta- “straight, true,” rās-
“to be right, straight, true;” Av. rāz- “to direct, put in line, set,” razan- “order;” cf. Skt. raj- “to direct, stretch,” rjuyant- “walking straight;” Gk. orektos “stretched out;” L. regere “to lead straight, guide, rule,” p.p. rectus “right, straight;” Ger. recht; E. right; PIE base *reg- “move in a straight line,” hence, “to direct, rule.”