Small Solar System body
A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, except satellites, orbiting the Sun shall be referred to collectively as 'Small Solar System Bodies' ".
This encompasses all comets and all minor planets other than those that are dwarf planets. Thus SSSBs are: the comets; the classical asteroids, with the exception of the dwarf planet Ceres; the trojans; and the centaurs and trans-Neptunian objects, with the exception of the dwarf planets Pluto, Haumea, Makemake, and Eris and others that may turn out to be dwarf planets.
Pythagorean astronomical system
While the earth and planets revolved around a central point in Philolaus's system, his could not be called a Heliocentric "solar system", because the central point the Earth and Planets revolved around was not the Sun, but the so-called Central Fire. This Fire was not visible from the surface of Earth—or at least not from the hemisphere Greece was located in.