Cone Nebula
The Cone Nebula is the small dark  cone at the lower center
of the image, that is just a fragment of this vast star-forming  
region, 2600 light-years distant.   The Hubble Space
Telescope took a closeup image of the cone, shown at the
right.  My image includes a wider one  degree field in the
constellation Monoceros (the Unicorn), next to Orion and
Gemini.  The blood-red glow arises from clouds of hydrogen
gas.  The ultraviolet light of nearby stars excites the Hydrogen
atom's solitary electron to a higher energy level.  The
Hydrogen atom then releases photons of discrete energy (and
thus discrete wavelength) when the gas makes a transition
back to a lower energy level.  For a more elegant discussion
of this process, click

Above the Cone Nebula, a loose triangular cluster of stars is
called the Christmas Tree cluster.  At the top of the image,
interstellar dust reflects the light of the brightest stars in the
cluster, glowing blue, which has been called the Foxfur
Nebula.  This blue glow is created by the same mechanism of
reflected starlight that causes our own skies to appear blue!

Imaging data:   Exposure times were 120 minutes red, 60
minutes green, and 80 minutes blue.  An ST2000XM camera
was used through a TEC 140 mm refractor at the Hidden
Lake Observatory.

Four years earlier, my image of this region was published in
Sky and Telescope magazine, accompanying a letter.  You
can see the article by clicking
click on image for full size