argument of perihelion The angle between the ascending node and the perihelion of an orbit around the Sun, measured in the orbital plane and in the direction of orbital motion. The argument of perihelion specifies the direction of the major axis of an orbit around the Sun and is one of the orbital elements. Related category • CELESTIAL MECHANICS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |