The degree of the zodiacal Sign posited on the Ascendant (q.v.), or cusp of the First House at birth, and generally considered the most important in the Nativity. The rising degree is based upon the exact moment of birth, or of the event for which the Figure is cast, and the correct geographical latitude and longitude. Should either factor be unknown the Figure is usually cast for sunrise, which places the Sun's degree upon the horizon, resulting in what is termed a Solar Figure. As it is based only on the Earth's apparent motion around the Sun some authorities term it a Heliard Figure.
ASTROLABE ENCYCLOPEDIA
