The Horsehead Nebula (also known as Barnard 33 in emission nebula IC 434) is a dark nebula in the constellation Orion. The nebula is located just to the south of the star Alnitak, which is farthest east on Orion’s Belt, and is part of the much larger Orion Molecular Cloud Complex. The nebula was first recorded in 1888 by Scottish astronomer Williamina Fleming on photographic plate B2312 taken at the Harvard College Observatory. The Horsehead Nebula 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 bears some resemblance to ahorse’s head when viewed from Earth.
The dark cloud of dust and gas is a region in the Orion Nebula where star formation is taking place. This stellar nursery, as it is known, can contain over 100 known organic and inorganic gases as well as dust consisting of large and complex organic molecules.
The red or pinkish glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. Magnetic fields channel the gases leaving the nebula into streams, shown as streaks in the background glow. A glowing strip of hydrogen gas marks the edge of the massive cloud and the densities of stars are noticeably different on either side.
The heavy concentrations of dust in the Horsehead Nebula region and neighbouring Orion Nebula are localized, resulting in alternating sections of nearly complete opacity and transparency. The darkness of the Horsehead is caused mostly by thick dust blocking the light of stars behind it. The lower part of the Horsehead’s neck casts a shadow to the left. The visible dark nebula emerging from the gaseous complex is an active site of the formation of “low-mass” stars. Bright spots in the Horsehead Nebula’s base are young stars just in the process of forming.
Imaging telescopes or lenses: Sky-Watcher Newton 8″
Imaging cameras: Canon EOS 550D / Rebel T2i
Mounts: Sky-Watcher HEQ5
Focal reducers: Sky-Watcher Coma corrector
Software: DeepSkyStacker, PHD guiding, photoshop
Dates: Oct. 20, 2012
Integration: 3.3 hours
Author: Ivan Jevremovic
AstroPhotography of the day by SPONLI 09 July 2014