M 78 is the brightest "reflection nebula" in the sky. The blue color is caused by
clouds of interstellar dust and gas reflecting the light of the stars within
them. M 78 is part of the Orion Complex, a vast cloud that includes M 42, M 43,
and the Running Man Nebula. M 78 is 1600 light years from earth, and is about 4
light years across.

This image was published in "Sky & Telescope", May 2011, page 77.

Image data:
Camera: STL-11000
Exposure: 3 hours luminance, RGB 30 minutes each (10 minute sub-frames)
Telescope: 12.5" Hyperion (first image for this telescope)