Pleiades - January 2013

About the image…

Image title – Pleiades.
Taken at – Observatorio del Teide (Canary Islands – Spain; 16º 30' 35" W, 28º 18' 00" N).
Telescope Takahashi FSQ-106ED, f/5
Instrument – Canon EOS 5D MkII.
Exposure – 13 x 900s @ ISO1000.
Image size 3.8º x 2.6º.
Software – PixInsight, Photoshop CS5.
Images taken and reduced by –
Pablo Rodríguez-Gil, Pablo Bonet, Sara Rueda, Jorge A. Pérez Prieto, Pedro A. González Morales.
Text – Pablo Rodríguez-Gil.

Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. The cluster sits on the Taurus Molecular. A molecular cloud is a large dense area of gas and dust made mostly of molecular hydrogen and helium. It is a birthplace of stars, which form from the material in the cloud. However, the Pleiades cluster is now known to have nothing to do with the molecular cloud. Contrary to common belief, the dust that forms a faint reflection nebulosity around the brightest stars is not the remnant from the progenitor nebula. In fact, computer simulations have shown that the Seven Sisters association was probably formed from a compact configuration that resembled the Orion Nebula within the last 100 million years. The hot, extremely luminous B-type stars of the Pleiades are actually passing through a dust cloud of the Taurus molecular complex (the brownish material in the picture), and their UV radiation causes the dust to shine with a characteristic blue colour.