This area in Monoceros (east of Orion) is a complex part of our galaxy.
The brightest area in this image is the glowing gas and stars that make
up the "Christmas Tree Cluster" (NGC 2264), with the Cone Nebula at its
"top" (on the lower right end of it, in this image). The Cone Nebula is
a cold cloud of hydrogen and dust that blocks light from the glowing emission
nebula behind it. Ultra violet light from bright stars in the region heat the
edges of the cloud, thus giving the Cone its glowing edge. The Cone Nebula is
7 light years long, and lies about 2500 light years from earth. Also visible
on the right side of the picture is the small fan-shaped Hubble's Variable
Nebula. It lies at about the same distance from earth as the Cone Nebula, but
is only 1 light year across. This nebula shows visible changes in appearance over
periods of just weeks, probably because clumps of thicker dust and gas pass in
front of the star which illuminates this nebula, casting shadows across the nebula.

Image data:
Telescope: Takahashi FSQ 106N
Camera: SBIG STL-11000, 5nm hydrogen alpha filter
Exposure: 3 1/2 hours (30 minutes x 7)