Barnard's Loop (Sh2-276)
DOI link for Barnard's Loop (Sh2-276)
Barnard's Loop (Sh2-276) book
A large emission nebula in the constellation Orion in the form of an arc centered on the Sword of Orion; the mid-point of the arc is at approximately RA 05 h 56 m, dec. −02°. The emission is thought to be caused by radiation pressure from the hot stars in the Sword region ionizing interstellar matter. It was discovered by E E Barnard.