But we cannot ignore Barnard's Loop (Sh 2-276):

"The loop extends over about 600 arcminutes as seen from Earth, covering much of Orion. It is well seen in long-exposure photographs, although observers under very dark skies may be able to see it with the naked eye [which reaches down to stars as faint as +8 in perfect conditions]." (Wikipedia)

Its apparent brightness is +5 and it is centered approximately at the Orion Nebula (M42).

"The stars within the Orion Nebula are believed to be responsible for ionizing the loop." (Wikipedia)