Orion molecular cloud
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Orion molecular cloud(OMC-1) A dense cloud of neutral molecular hydrogen lying slightly behind, but in contact with, the Orion nebula. It is part of a system of molecular clouds in the Orion constellation, and is an example of a photodissociation region seen face-on. It has a total mass of about 500 solar masses and has a temperature ranging up to 100 K. It is a very bright infrared source at a wavelength of 50 μm with a luminosity 105 times greater than the Sun's. It is likely that the Trapezium stars condensed from the same molecular cloud. Also associated with OMC-1 are the strong infrared sources, the BN object and Kleinmann-Low nebula, which together form the BNKL complex. Higher resolution measurements indicate that the center of the KL nebula consists of a cluster of small infrared sources that may be evolving toward the stage the Trapezium stars have already reached.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006