Astronomy Picture of the Day

Explanation: What creates the colours of the Cocoon Nebula? The Cocoon Nebula, catalogue.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.e.ed as IC 5146, is a strikingly beautiful nebula located about 4,000 light years away toward the constellation of the Swan (Cygnus). Inside the Cocoon Nebula is a newly developing open cluster of stars. Like other stellar nurseries, the Cocoon Nebula holds, at the same time, a bright red emission nebula, blue reflection nebulae, and dark absorption nebulae. Given different mixtures, these three processes create a host of colours in this image taken recently by the Canada-France-Hawaii Telescope (CFHT) in Hawaii, USA. Speculation based on recent measurements holds that the massive star towards the left of the picture opened a hole in an existing molecular cloud through which much of the glowing material flows. The same star, which formed about 100,000 years ago, now provides the energy source for much of the emitted and reflected light from this nebula.