What is a Brown Dwarf?

Sub-brown dwarfs, planetary-mass objects, have a mass lower than the lower limit for brown dwarfs (about 13 times the mass of Jupiter). Sub-brown dwarfs are formed in the form of stars through the collapse of gas clouds, rather than through the core of an arched disk, or accretion.

Sub-brown dwarf

The secondary brown dwarf is

An alternate definition contains the same mass range (below a brown dwarf, but within the planet's mass range), but is not affected by the gravitational influence of any star. These are usually free-floating planets, and this usage is a temporary definition of extrasolar planets by the International Astronomical Union.