Cone Nebula 
The celestial unicorn isn’t much to look at. Monoceros includes only a smattering of stars bright enough to see with the unaided eye — and none of them represents the unicorn’s horn. But there is a horn-like structure right about where the horn should be. It’s so faint, though, that it shows up only in long-exposure photographs.
The Cone Nebula is shaped a bit like a traffic cone. It’s a dark cloud of gas and dust that lies in front of a bright cloud.
The Cone is at the edge of NGC 2264, a complex of young stars and giant, billowing clouds of gas and dust. The stars light up the surrounding hydrogen gas, making much of the region shine reddish-pink.
But the complex also includes regions that are filled with colder gas and dust. They form dark streamers and blobs against the glowing background.
The Cone Nebula is the most prominent. Its shape is easy to pick out, with the narrow end of the cone pointing toward the center of NGC 2264.
The Cone spans about seven light-years — half-again the distance from the Sun to its closest neighbor stars. A hot star close to the Cone is stripping away material from its top. Yet the gas and dust deep inside the cone may remain cold enough and dense enough to give birth to new stars. If so, then one day the energy from these stars will erode the Cone from the inside — stripping away this faint “horn” for the unicorn.
Script by Damond Benningfield, Copyright 2014