Thursday, September 3, 2009

What is it? An apple core, dumbbell, football or a planet?

Click on image for a larger view
345 years ago, while looking for comets, Charles Messier discovered this nebula in the sky and numbered it the 27th object in his list of objects that were not comets. He called it an "oval nebula". Sixty four years later, in 1828, another astronomer, John Herschel, wrote that it was shaped like a dumbbell, and it has been called that ever since. Looking through a telescope, I always have the impression that it looks like an apple core. With long exposure photography, dimmer areas become visible turning it into a football. These type of deep sky objects are also known as planetaries. Definitely not planets, in the 18th century astronomers coined them planetaries because they looked very similar to the gas giant planets, mostly round and diffuse. Unfortunately, that name has also stuck.
A planetary nebula is something that humanity will see up close and personal some time in the distant future. At that point in time, about 5 billion years, it will destroy the Earth and everything on it. What you see in the Dumbbell Nebula is the death throes of a star similar to our Sun. This dying star, which you can see at the center of the nebula, had previously grown into a Red Giant, and is now pulsating and shedding off it's outer layers into space. The extremely hot central star radiates ultraviolet light into these outer layers making it glow.
Technical Photo Info
Camera: Q453 CCD by CCD-Labs
Telescope: 10" f/5.5 Newtonian with a Coma Corrector in the optical path
Mount: Celestron CGE
Guidescope: 60mm Dia., 400mm Focal Length
Guide Camera: Q-Guider by CCD-Labs
Exposure Length: 7 X 10 min exposures for a total of 70 minutes
Darks: 1 Dark to create a Dark Pixel Map to get rid of hot pixels
Flats: None
Biases: None
Aligned and Stacked in Nebulosity with final processing in Photoshop

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