A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently to no longer emit significant heat or light. Because the time required for a white dwarf to reach this state is calculated to be longer than the current age of the universe (13.8 billion years), no black dwarfs are expected to exist in the universe at the present time. The temperature of the coolest white dwarfs is one observational limit on the universe's age.
A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently, to no longer emit significant heat or light Because the time required for a white dwarf to reach this state is calculated to be longer than the current age of the universe (13.8 billion years) no black dwarfs are expected to exist in the u.niverse at the present time. The temperature of the coolest white dwarfs is one observational limit on the universe's age.