Coalsack Nebula

The Coalsack Nebula, catalogued as Caldwell 99, is one of the most prominent dark nebulae visible to the naked eye. It lies in the southern constellation Crux (the Southern Cross) and appears as a striking dark patch against the bright backdrop of the Milky Way, near the bright stars Acrux and Becrux.

This vast cloud of interstellar dust and gas spans about seven degrees across the sky and is located roughly 600 light-years away. It effectively blocks the light of the dense star field behind it, therefore creating the dramatic contrast that gives it its name — the “Coalsack.” In the Southern Hemisphere, it is one of the most recognizable features of the night sky, often visible to the unaided eye even under moderately dark conditions.

The Coalsack is part of a larger network of dark clouds that include the Chamaeleon and Musca nebula complexes, representing the densest regions of the nearby interstellar medium where new stars may eventually form.

The last time I imaged this dark nebula in 2006 at the Tivoli astrofarm. Data calibration and registration was done with DeepSkystacker, the final processing was done with PixInsight. The result was as follows:

The images were taken with the following equipment:

Date 2006
Location: Tivoli, Namibia
Telescope: Tamron 28-300mm lens
Focal length [mm]: 70
Focal ratio: 4.5
Mount: Vixen Atlux
Camera: Canon 300 Da
Filter: OSC
Exposure time [min]: 36
Resolution: 21.8″/px

The first time I imaged this dark nebula in 2005 at the astrofarm Hakos. Data calibration and registration was done with DeepSkystacker, the final processing was done with PixInsight. The result was as follows: