Mystery Objects: The Largest Known Population of ‘Immortal’ Brown Dwarfs Revealed
It is estimated that up to 60 billion brown dwarfs make their home in the Milky Way. Because these elusive celestial objects do not fuse hydrogen in their core, they spend their lives cooling as they lose that gravitational energy from their formation, morphing as they age from looking like a low-mass star to looking like Jupiter. Every brown dwarf that was ever created still exists because they can’t fuse hydrogen, giving them a calm, sustained existence on the vast timeframe of the cosmos.