Outline of the Solar System
Solar System – gravitationally bound system comprising the Sun and the objects that orbit it, either directly or indirectly. Of those objects that orbit the Sun directly, the largest eight are the planets (including Earth), with the remainder being significantly smaller objects, such as dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly, the moons, two are larger than the smallest planet, Mercury.
Celestial coordinate system
The heliocentric ecliptic system describes the planets' orbital movement around the Sun, and centers on the barycenter of the solar system (i.e. very close to the center of the Sun). The system is primarily used for computing the positions of planets and other solar system bodies, as well as defining their orbital elements.