February 10, 2007
This is the famous Pleiades open star cluster in the constellation Taurus, also known as Messier object 45 (M45). The arrival of this familiar star cluster in the evening sky is a precursor of winter. The Pleiades, also known as the Subaru, Matariki, Freyja's hens, Kartika, Krittika, and the "Seven Sisters," have been revered by many different cultures over the centuries. Although they're well-known to anyone who studies the night sky, what's less well-known is that the entire region is swathed in a beautiful blue reflection nebulosity. This nebulosity is composed of dust which scatters the blue light of the young, hot stars far more efficiently than the longer wavelengths, so the blue photons are preferentially scattered into our ground-based telescopes. The Pleiades lies relatively close to the Earth, at a mere 440 light years distance. The image above results from an international, internet collaboration between Professor Greg Parker, who acquires the data from his New Forest Observatory in Brockenhurst, United Kingdom, and Noel Carboni, an expert image processor who transforms the raw digital data into beautiful deep-sky images. It was acquired in December of 2006 from New Forest, Hampshire, England. The total imaging time was 5 hours and 48 minutes.