Monoceros R2 Molecular Cloud
The Monoceros R2 molecular cloud, and this is only a portion of it. It is a large area of star formation, as can be seen in the huge bright red nebula just below the center of the image. This image was taken in Hydrogen-Alpha and Sulphur filters.
(Image credit: T.A. Rector (University of Alaska Anchorage) and N.S. van der Bliek (NOAO/AURA/NSF))