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Horsehead Nebula

Barnard 33

Proper NameHorsehead Nebula
NGC/IC NumberAssociated with IC 434
Other DesignationsBarnard 33
Right Ascension5h 40m 59s
Declination-2° 27' 30"
Distancec.1,600 light years
c.500 parsecs
DimensionsApparent: 1° 6' x 4'
Actual: 2.7 x 1.8 light years
Optimum VisibilityDecember / January
The Horsehead Nebula

This plume of dark material makes up one of the most recognisable objects in the night sky - the Horsehead Nebula in Orion. The horsehead shape is visible against the glowing pink of the emission nebula IC 434.

The famous dark Horsehead Nebula lies in the central regions of Orion. It is closely associated with Alnitak, the eastern star of Orion's Belt, and with nearby Sigma Orionis.

Relative Galactic Position of the Horsehead Nebula

Like our Sun, the Horsehead Nebula lies in that part of the Galactic spiral known as the Orion Arm. It forms part of a complex collection of nebulae scattered throughout this part of the Galaxy, centred in the constellation of Orion.

A famous dark nebula in the constellation of Orion. A plume of obscuring dust takes a form very reminiscent of a horse's head, dark against a glowing background.

The Horsehead Nebula is located in Orion. In the sky, it appears a little to the south of Alnitak at the eastern end of the three stars that make up Orion's Belt. In fact it is considerably further away than the Belt star Alnitak, and the radiation that makes this dark nebula visible against its glowing background comes from nearby Sigma Orionis.

The Horsehead is in fact a small segment of the immense Orion Molecular Cloud, formed from a tendril of gas and dust that stands out against the pale pink glow of a swathe of ionised hydrogen within the Cloud, itself designated IC 434. This dark strand of matter has a twist at its tip, folding back on itself in a way that creates the distinctive horsehead form from which the nebula takes its name.

A dense accumulation of material, this nebula creates a region in which new stars are being formed, especially in the denser regions that form the 'neck' of the horse's head.

A view of the sky around the Horsehead Nebula. The dark shape of a horse's head in the centre of this image is silhouetted against the pale nebula IC 434. The whole complex lies southward of the Alnitak, the eastern star of Orion's Belt. Imagery provided by Aladin sky atlas


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