Dark nebulae are astronomical objects. They do not emit or reflect light. They are seen when they hide stars and galaxies behind them.
The astronomer Edward Emerson Barnard compiled a list of dark nebulae known as the Barnard Catalogue of Dark Markings in the Sky, or the Barnard Catalogue for short. The nebulae listed by Barnard have become known as Barnard objects.
These are the best-known dark nebulae: