28.7.14

Picture - The Horsehead Nebula from Blue to Infrared

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The Horsehead Nebula from Blue to Infrared
Image Credit & Copyright: Optical: Aldo Mottino & Carlos Colazo, OAC, Córdoba; Infrared: Hubble Legacy Archive

Explanation: One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark,molecular cloud. Also known as Barnard 33, the unusual shape was firstdiscovered on aphotographic plate in the late 1800s. The red glow originates fromhydrogengas predominantly behind the nebula, ionized by the nearby bright starSigma Orionis. The darkness of theHorsehead is caused mostly by thickdust, although the lower part of theHorsehead's neck casts a shadow to the left. Streams of gas leavingthe nebula are funneled by a strongmagnetic field. Bright spots in theHorsehead Nebula's base are young stars just in the process of forming. Light takes about 1,500 years to reach us from theHorsehead Nebula. The above image is a digital combination of images taken in blue, green, red, and hydrogen-alpha light from the Argentina, and an image taken in infrared light by the orbiting Hubble Space Telescope.

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