The Carina Nebula, with an overall diameter of more than 200 light years, is one of the outstanding features of the Milky Way.

A 'keyhole' in space

The picture is a montage assembled from four different April 1999 telescope observations. The images were taken with Hubble's Wide Field Planetary Camera 2, which used six different colour filters.

Dominating the image is a large circular feature which is part of the so-called Keyhole Nebula, named in the 19th Century by Sir John Herschel. This region, seven light years across and about 8,000 light years from Earth, is located next to an explosive variable star, eta Carinae, which lies just outside the image.

Hot and heavy

The Carina Nebula also contains several other stars that are among the hottest and most massive known - each is about 10 times hotter and 100 times more massive than our Sun.

The Keyhole region contains bright filaments of hot gas as well as dark silhouetted clouds of cold molecules and dust, all of which are in rapid, chaotic motion. The high resolution of the Hubble images also reveals numerous small dark globules that may be in the process of collapsing to form new stars.

The pronounced pillars seen in one of the massive dust clouds appear to point toward a luminous, massive star located just outside the image. This star may be responsible for illuminating and sculpting them because of its high-energy radiation and stellar wind of high-velocity ejected material.

The large dark clouds may eventually evaporate, or, if there are sufficiently dense condensations within them, give birth to small star clusters.