October 12, 2010

The Great Nebula in Orion (9&10-2010)


This nebula is one of the most famous in the sky. It is visible without optical aid in the belt of Orion's sword. It is basically a huge cloud of gas and dust, mostly hydrogen, that is coalescing to form stars. The stars just lower left of center are newly formed and are sending out the radiation that makes the clouds of gas glow. The four bright stars are called the Trapezium. Actually, there is a knot of stars there. This image was shot at a focal length of 500mm, not enough resolution to allow the other stars to be seen clearly. This nebula is a stunning sight in a telescope. These colors are false, but in a large scope the entire nebula takes on a greenish glow that contrasts with the stars and with the dark sky behind it.

This image is about 2 hours per narrowband channel: Ha (mapped to green), OIII (blue), and SII (red). I also took a string of 30-second Ha exposures designed to show the four stars at the core of the nebula without totally blowing it out. Processing was done in Neb2, Maxim DL, Registar, and PS CS3. This is another image gathered with the 120mm achromat and the Atik 16. It's turned out to be a nice combination.

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