Horsehead Nebula Imaged by Peter Campbell-Burns

The Horsehead Nebula (also known as Barnard 33 in bright nebula IC 434) is a dark nebula in the constellation Orion located just below Alnitak, the star furthest left on Orion’s Belt.  It is part of the larger Orion Molecular Cloud Complex and is approximately 1500 light years from Earth. It is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases, which is similar to that of a horse’s head.  Its red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead’s neck also casts a shadow.

Lookup the Horsehead Nebula on SEDS

Horsehead Nebula - click to enlarge