出典:Wikipedia
出典:『Wikipedia』 (2011/06/12 18:04 UTC 版)
Barnard's Loop (catalogue designation Sh 2-276) is an emission nebula in the constellation of Orion. It is part of a giant molecular cloud which also contains the bright Horsehead and Orion nebulae. The loop takes the form of a large arc centred approximately on the Orion Nebula. The stars within the Orion Nebula are believed to be responsible for ionizing the loop.