Coalsack Nebula
Object Data
- Catalog Designation
- C99
- Type
- DarkNebula
- Constellation
- Crux
- Magnitude
- 12.0
- Right Ascension
- 12h 47m 48.0s
- Declination
- -63° 00' 00.0"
- Distance
- 600 light-years
- Angular Size
- 420
Survey Image
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About Coalsack Nebula
Description
The Coalsack Nebula is the most prominent dark nebula in the sky, located about 600 light-years away in Crux. It spans roughly 7 by 5 degrees and appears as a striking dark patch against the bright southern Milky Way, easily visible to the naked eye.
Observing Tips
Best seen with the naked eye or binoculars from the southern hemisphere. No telescope is needed — the Coalsack is visible as an obvious dark void next to the Southern Cross. Look for the subtle variations in opacity and the small bright cluster NGC 4609 (C98) at its edge. Best in autumn and winter.
History
Known to southern hemisphere cultures for millennia. Aboriginal Australians see it as the head of an Emu in the sky. European explorers noted it from the early 1500s. It was one of the first dark nebulae recognized as an interstellar dust cloud rather than a true hole in the stars.
Fun Facts
The Coalsack is not completely opaque — background stars can be seen through its thinner regions. It contains about 3,500 solar masses of dust and gas. The nearby Southern Cross (Crux) makes the Coalsack one of the most recognizable features of the southern Milky Way.
Community Photos (1)
Credit: ESO. License: CC BY 4.0. (Wikimedia Commons)
Skybred Mar 2, 2026