The Cone Nebula, or NGC 2264, is a dark nebula located 2,500 lightyears away in the Monoceros constellation. The nebula is 7 lightyears long and is packed full of dense gas and dust - the ingredients necessary for star formation - making it a perfect stellar factory. This tempestuous deep-sky region contains scorching hot young stars that are eroding and carving out the dark nebula, also emitting blasts of powerful ultraviolet light that can be seen illuminating the edges of the dense cosmic cloud. The NGC 2264 region also contains an open star cluster known as the Christmas Tree Cluster, as it forms a sparkling triangular shape that makes it look rather like a festive fir.
One of the most iconic nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming.
The two carved-out cavities of the Flame nebula and NGC 2023 were created by the destructive glare of recently formed massive stars within their confines. They can be seen tracing a spine of glowing dust that runs through the image. The Flame nebula sits adjacent to the star Alnitak, the easternmost star in Orions belt, seen here as the bright blue star near the top left of the image.
