IC 434 - Horsehead Nebula - ChuckNovice

Constellation: Orion Object type: Emitting nebula Distance: 1,500 light-years Magnitude: 7.3 Discovered by Williamina Fleming in 1888 Fun Facts! Several remarkable objects can be seen in this image: IC 434, which refers to the nebula behind Barnard 33, the Horsehead Nebula (which is a dark nebula), but also NGC 2023 (the small blue reflection nebula below the Horsehead) and NGC 2024 (the Flame Nebula), illuminated by the blue supergiant star Alnitak (one of the 3 stars in Orion's belt). The Horsehead would be luminous if it weren't located in front of IC 434, whose emission nebulae are brighter because they are ionized by the star Sigma Orionis at the top of the image. As the base of the head is the site of new star formation, the shapes of this structure evolve rapidly on cosmic timescales: within a few hundred thousand years, the horse's head will be unrecognizable... and will have completely disappeared within 5 million years.