Using the LABOCA camera on the Atacama Pathfinder Experiment (APEX) telescope on the plateau of Chajnantor in the Chilean Andes, a team of astronomers led by Thomas Preibisch imaged the cold dusty clouds from which stars form in the Carina Nebula in submillimetre light. At this wavelength, most of the light seen is the weak heat glow from cosmic dust grains.
Carina Nebula (ESO/APEX/T. Preibisch et al., N. Smith, University of Minnesota/NOAO/AURA/NSF)
The image therefore reveals the clouds of dust and molecular gas — mostly hydrogen — from which stars may form. At -250ºC, the dust grains are very cold, and the faint glow emanating from them can only be seen at submillimetre wavelengths, significantly longer than those of visible light. Submillimetre light is, therefore, key to studying how stars form and how they interact with their parent clouds.
The APEX observations are shown here in orange tones, combined with a visible light image from the Curtis Schmidt telescope at the Cerro Tololo Interamerican Observatory. The result is a dramatic, wide-field picture that provides a spectacular view of Carina’s star formation sites. The nebula contains stars with a total mass equivalent to over 25 000 Suns, while the mass of the gas and dust clouds is that of about 140 000 Suns.
However, only a fraction of the gas in the Carina Nebula is in sufficiently dense clouds to collapse and form new stars in the immediate future (in astronomical terms, meaning within the next million years). In the longer term, the dramatic effects of the massive stars already in the region on their surrounding clouds may accelerate the star formation rate.
The Carina Nebula is some 7500 light-years distant in the constellation of the same name (Carina, or The Keel). It is among the brightest nebulae in the sky because of its large population of high-mass stars. At about 150 light-years across, it is several times larger than the well-known Orion Nebula. Even though it is several times further away than the Orion Nebula, its apparent size on the sky is therefore about the same, making it also one of the largest nebulae in the sky.
