Related Words

Ecliptic: The sun's apparent path across the sky that tracks a circle through the celestial sphere.

Obliquity Of The Ecliptic: The angle between the plane of the ecliptic and the plane of the equator. It now measures about 23°27', and is decreasing at the rate of one minute in 128 years.

Precession Of The Equinoxes: The gradual westward shift (about 50' each year) of the equinoctial points along the ecliptic due to the ecliptic due to the rotational movement of the poles of Earth's axis. This phenomena . . . View Full Definition

Regiomontanus: The German astrologer (fifteenth century) who devised the house system that bears his name. This system is based upon twelve equal divisions along Earth's equator projected upon the ecliptic.

Precession: The circular motion of Earth's axis around the pole of the ecliptic, caused by the gravitational pull of the Sun and Moon on the bulging part of the equator. One complete revolution takes ap . . . View Full Definition

Placidean Houses: The house system devised by the Spanish monk, Placidus de Tito (seventeenth century). Placidus' system, still widely used today, is based on the trisection of nocturnal and diurnal semi-arcs . . . View Full Definition

Tropical Signs: Cancer and Capricorn; so-called because they occupy parts of the ecliptic where the Sun reaches its farthest point north (Tropic of Cancer) and south (Tropic of Capricorn). The Sun's ingress . . . View Full Definition

Planetary Node: The point at which a planet's path intersects the ecliptic; declination, 0°. The term is usually reserved for nodes other than the Moon's Nodes.

Vertex: The point found in the western section of a horoscope that indicates the intersection of the ecliptic and prime vertical, called the 'third angle of a horoscope'. This point and its opposite . . . View Full Definition

Mean Sun: A fictitious sun which is assumed to move in the celestial equator at a uniform speed corresponding to the average angular speed of the real Sun in the ecliptic, the mean sun being alternate . . . View Full Definition