A mass of nebulous material and star clusters in northern Puppis, the Skull and Crossbones Nebula lies southward along the Milky Way from Sirius in Canis Major. There are indications that this is not in fact a single nebula, but instead represents several distinct phenomena sharing a similar line of sight from Earth, while actually being widely separated from one another in space.
This complex star-forming region lies in the northern regions of Puppis, less than two degrees southward of the starAzmidi or Xi Puppis. It consists of a relatively young hydrogen nebula, with at least two associated star clusters. These clusters, Haffner 18 and Haffner 19, collectively share the designation NGC 2467 with the surrounding nebula. Dark lanes of dust run through the nebula, giving it a very approximately face-like appearance from which it takes its common names of the Skull and Crossbones Nebula or the Mandrill Nebula.
The distances to the nebula and its clusters are difficult to assess with certainty. Some measurement methods suggest a distance of a little under 1,400 light years, while other approaches imply that the complex is considerably more distant than this. The gases of the nebula are illuminated by several hot young stars, estimated to be no more than few million years old. Most notable among these is V402 Puppis or HD 64315, an intensely hot O-typestar that outshines the other stars in the surrounding area.
The cluster Haffner 18 is notable for being surrounded by a near-spherical bubble of nebulous material, a region of gas ionised by a brilliant bluestar at the heart of the cluster (the resulting sphere forms one 'eye' of the Skull or Mandrill referred to by the nebula's common name). As well as the stars of the various clusters within the nebula, numerous protostars are also emerging from scattered locations within its gas and dust.