Complex sentence: A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or light.These object were theoretically predected as early as 1960s by Shiv S. Kumar in 1962.
Split into simpler sentences: A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or light. These objects were theoretically predicted as early as 1960s by Shiv S. Kumar in 1962.