Horsehead Nebula

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The Horsehead Nebula (also known as Barnard 33 in bright nebula IC 434) is a dark nebula in the constellation Orion. The nebula is located just below Alnitak, the star furthest left on Orion's Belt, and is part of the much larger Orion Molecular Cloud Complex. It 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. The shape was first noticed in 1888 by Williamina Fleming on photographic plate B2312 taken at the Harvard College Observatory.

Hubble image of Horsehead Nebula.

ESO image of Horsehead Nebula.

Amateur Image of the Horsehead Nebula Region South of the star Alnitak in Orion's Belt also showing NGC 2023 and the Flame Nebula (south is to the right in this image)

The 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 casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming.

[edit] See also

• Horsehead Nebula in fiction

[edit] External links

• The Horsehead Nebula @ The Electronic Sky
• Hubble Observes the Horsehead Nebula
• The discovery of early photographs of the Horsehead nebula, by Waldee and Hazen
• The Horsehead Nebula in the 19th Century, by Waldee
• Detection of new nebulae by photography, by Pickering
• Horsehead Nebula at ESA/Hubble
• The Horsehead Nebula at the Astro-Photography site of Mr. T. Yoshida.
• The Horsehead Nebula on interactive astro-photography survey at Wikisky.org
• The Horsehead-Nebula imaged with a semiprofessional amateur-telescope