List of planet types



The following is a list of planet types by their mass, orbit, physical and chemical composition, or by another classification.

The IAU defines that a planet in the Solar System must orbit around the Sun, has enough mass to assume hydrostatic equilibrium, and has "cleared its neighborhood". The working definition of an exoplanet is as follows:

"* Objects with true masses below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity) that orbit stars, brown dwarfs or stellar remnants and that have a mass ratio with the central object below the L4/L5 instability (M/Mcentral < 2/(25+$\sqrt{621}$)) are 'planets' (no matter how they formed).
 * The minimum mass/size required for an extrasolar object to be considered a planet should be the same as that used in our Solar System."

Under the IAU definition, true or "major planets" can be distinguished from other planetary-mass objects (PMOs), such as dwarf planets and sub-brown dwarfs. Nonetheless, certain planet types have been applied to other planetary-mass objects; the Pluto–Charon system has been referred to as "double dwarf planets", for instance.