Solar System
The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, such as the five 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.
Astronomical system of units
The astronomical unit of mass is the solar mass. The symbol is often used to refer to this unit.
The solar mass (), , is a standard way to express mass in astronomy, used to describe the masses of other stars and galaxies. It is equal to the mass of the Sun, about times the mass of the Earth or 1 048 times the mass of Jupiter.