ecliptic coordinates

In astronomy, system for measuring the position of astronomical objects on the celestial sphere with reference to the plane of the Earth's orbit, the ecliptic.

Ecliptic latitude (symbol β) is measured in degrees from the ecliptic (β = 0°) to the north (β = 90°) and south (β = − 90°) ecliptic poles.

Ecliptic longitude (symbol λ) is measured in degrees eastward along the ecliptic (λ = 0° to 360°) from a fixed point known as the first point of Aries or the vernal equinox. Ecliptic coordinates are often used to measure the positions of the Sun and planets with respect to the Earth.

Ecliptic latitude and longitude are sometimes known as celestial latitude and longitude. The ecliptic longitude of the Sun (solar longitude) is a convenient measure of the position of the Earth in its orbit.