This is a Brown Dwarf and it was an L Type Brown Dwarf due to the increasing temperature of the nebula it was born in, then the brown dwarf to cool to a T then Y Type at a low temperature like a habitable planet there are smaller than red dwarfs but about 50 times the mass of Jupiter
Their life span is about 10 Quadrillion Years or lesser because when a brown dwarf collides with another forming a red dwarf will then die in trillions of years
