Editor’s Note:Imaged above is a conceptual, hypothetical illustration of a black dwarf. These types of stars have not been observed yet, since the time required for a white dwarf to reach this state is calculated to be longer than the current age of the universe of 13.7 billion years, no black dwarfs are expected to exist in the universe yet.[*]
White dwarfs are stable because the inward pull of gravity is balanced by the electrons in the core of the star repulsing each other.
With no fuel left to burn, the hot star radiates its remaining heat into the coldness of space for many billions of years. In the end, it will just sit in space as a cold dark mass sometimes referred to as a black dwarf.