The path traced by the Sun around the sky over the course of the year. The ecliptic plane is the plane of the Earth's orbit around the sun. It is the natural plane of reference for the ecliptic coordinate system . The angular separation between two components of a binary system. At maximum elongation the components are most widely separated on the sky.
Maximum elongation corresponds to quadrature .
The times when the Sun crosses the celestial equator. A circle formed by the intersection of the sphere with a plane containing the center of a sphere. This is the largest circle that can be drawn on a sphere. The shortest distance between two points on a sphere is always a part of a great circle. Refers to the sun.