About This Photograph
This enigmatic formation of gas and dust lies in the constellation of Monoceros (the Unicorn) not far off the left arm of Orion. This is a close-up of a small section of a much larger complex, generally known as the Christmas Tree cluster. The mysterious Cone Nebula is also a part of this same cloud.
The red regions of this nebula are caused by hydrogen gas that has been stimulated to emit its own light by the copious ultraviolet radiation coming from the hot, blue stars of the cluster. The blue areas shine by a different process: they are mainly dust clouds that reflect the bluish light of the same stars.
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