The solar system comprises our Sun and the retinue of celestial objects gravitationally bound to it. Traditionally, this is said to consist of the Sun, nine planets and their 158 currently known moons; however, a large number of other objects, including asteroids, meteoroids, planetoids, comets, and interplanetary dust, orbit the Sun as well.
Although the term "solar system" is frequently applied to other star systems and the planetary systems which may comprise them, it should strictly refer to our system specifically: the word "solar" is derived from the Sun's Latin name, Sol (and the term sometimes appears as Solar System). When talking about another stellar system (or planetary system), including the star(s) and bodies associated with them through gravity, it is usual to shorten it to "the <name> system" (e.g. "the Alpha Centauri system" or "the 51 Pegasi system").
In September 2003, astronomers at Mount Palomar Observatory discovered 2003 UB313, a distant object currently being considered as a possible new planet as it is larger than Pluto (the status of which has also been contentious). Later, astronomers at the Keck Telescope revealed that it has a moon in orbit around it.
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