Helio cent rice, Helio centrical

[Gr. helios, and kentron, centre.] ( Astron.) Pertaining to, or appearing to be seen from, the sun's centre; as, the helio centric place of a planet. Heliocentric parallax . See PARALLAX. Heliocentric place , the latitude, longitude, . of a planet or heavenly body. The heliocentric latitude of a planet is the angle of the sun's centre, formed by the projection of its radius vector on the elliptic and the straight line drawn from the centre of the sun to the first point of Aries. Similarly, the heliocentric longitude of a planet is the angle formed by the straight line which joins the centres of both planet and sun, with the plane of the ecliptic. The greatest heliocentric latitude is consequently equal to the inclination of the planet's orbit. Heliocentric System n. ( Astron .) The system which regards the sun as the centre of our solar system. This theory was first propounded by Aristarchus of Samos, and afterwards established by Copernicus. As put forth by him, it needed only Newton's hypothesis of gravitation to complete the system of modern astronomy.