Ecliptic coordinate system
The ecliptic coordinate system refers to a coordinate system based on the ecliptic and vernal equinoxes. The orbital plane of the earth revolving around the sun is inclined at 23.5 ° to the equator of the celestial sphere, and the equator of the ecliptic and celestial crosses at the two intersections. In astronomy, the vernal equinox is used as the reference point of the ecliptic.