Fusor is a cosmic body that is capable of starting nuclear fusion in its core, at any point in its lifetime. Fusor includes stars, stellar remnants and brown dwarfs.

The term was coined by astrophysicist Gibor Basri and was proposed at the 2003 IAU conference. The definition proposed by Basri only mentions nuclear fusion, not any particular form of nuclear fusion. So the lowest possible mass for a fusor is roughly 13 times that of Jupiter, at which point deuterium fusion stars. Though, it is significantly smaller than the point at which sustained hydrogen fusion becomes possible around 60 times the mass of Jupiter.

See also

• Star
• Planemo