Zodiac on the ecliptic plane

The annular region on the north and south sides of the ecliptic on the celestial sphere. There are twelve constellations in the zodiac, and the sun always appears in the same constellation in a month. According to the arrangement order of the constellations, the sun passes through one of the twelve constellations every month, and the trajectory of the sun passing through the zodiac is called the zodiac.

In astronomy, celestial coordinate system is a coordinate system that describes the position of objects in the sky. Similar to the geographical coordinate system we use on the earth's surface, celestial coordinate system changes with the grid of coordinates projected on the celestial sphere. The plane that divides the sky into two equal hemispheres along the great circle is called the fundamental plane, and this coordinate system will only change because of the difference of the fundamental plane. The basic plane in the geographical coordinate system is the equator of the earth. The name of each coordinate system depends on the choice of basic principles. The following are different coordinate system names:

Horizon coordinate system

Equatorial coordinate system ecliptic coordinate system

Galaxy coordinate system

Supergalaxy coordinate system