Dark Brown Dwarfs, Dark Brown Dewalls, Black Holes, Black Nebulae, Black Hole

The number of stars that are out there that we cannot see is vast. Massive compact halo objects, these small stars, dead remnants of stars, the brown dewalls, so to speak, that have cooled down and we just can't see them. Black holes is one possibility. Some theories seem to suggest that these impurities really do act as a catalyst in causing a differential burning through of the nuclear fuel. Who knows what effects these things could have in real life?