The Cone Nebula, named because of its distinct conical shape, is a nebula in the southern part of NGC 2264, a catalogue number that refers to both the Nebula and the Christmas Tree Cluster. Much like the Horsehead Nebula, the Cone Nebula gets its shape from an intervening, straight sided, dark absorption nebula of cold molecular hydrogen and dust. This dark nebula is the largest of the clouds in the NGC 2264 region. The Christmas Tree Cluster is the collection of bright stars in the middle of this image.

The objects are located in the relatively modern constellation of Monoceros, which we first know to have been acknowledged in 1612. It is a region of hydrogen nebulae, ionised by the star S Monocerotis (S Mon), which is the brightest star in NGC 2264, clearly visible in the centre of this image. It is thought to be at least 8,000 times more luminous than our Sun and about twice as large, with a radius of 1.3 million kilometres. S Mon has a spectral type of O7, meaning that the star is blue coloured and its calculated effective temperature is about 25,000 Kelvin.

The NGC 2264 region is thought to be a place of new star formation, as within and around the hydrogen nebulae are many recently formed stars, although they cannot be observed regularly as they are almost completely hidden by dense interstellar matter. These stars can be observed using infra-red, and are estimated to be very young in comparison to the surrounding nebulae.

There is one further object in this image, the Fox Fur Nebula. It is located just to the right of S Mon and has a very ruffled, fur-like appearance.