Sunday, October 16, 2011
I've always seen pictures of the Horsehead Nebula, but I just realized that I know nothing about it. So I thought this would be a good opportunity to figure that out.
The Horsehead Nebula, also known as Barnard 33, is located on the east side of Orion's Belt, about 1500 light years away from the Earth. It gets its name because the shape of the dust and gas clouds resembles that of a horse's head when views from the Earth. The Horsehead Nebula is a dark nebula, which means that it is a very dense interstellar cloud. In this case, the Horsehead Nebula obscures the light of the emission nebula IC 434, in which it is located.
The red glow around the nebula comes from hydrogen gas that is ionized by the star system Sigma Orionis. Sigma Orionis is system of five stars in Orion. The main components of the system are two hydrogen-fusing dwarf stars in binary, Sigma Orionis AB. The bright spots just inside the base of the nebula are young stars being born.