JavaScript is required
JPL Logo
Image

What is a Brown Dwarf?

April 9, 2020
This illustration shows brown dwarfs are more massive than planets but not quite as massive as stars.

Brown dwarfs are more massive than planets but not quite as massive as stars. Generally speaking, they have between 13 and 80 times the mass of Jupiter. A brown dwarf becomes a star if its core pressure gets high enough to start nuclear fusion.