Photographic wanderings

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Pacman, video game cult early 80′s and cartoon, also gave its name to a nebula in the constellation Cassiopeia. Beginners in astronomy ask me why. I will just tell them to watch what Pacman looked like and then to look at the photograph below.

The nebula NGC281 or Pacman is a HII region (emission nebula consisting of clouds of gas containing mainly hydrogen). It is approximately 10,000 light years from Earth and its diameter is about 80 light years. In the sky, the angular diameter of 35′ is slightly larger than the Moon.

As for the image, the 3h15 exposure are welcome to limit noise in areas slightly darker. The image seems to lack sharpness. The stars are a bit muddy. Problem with focus, guiding or atmosphere: I do not know.

Anyway, I have another version of this nebula as that made with 1 h exposure at the Col du Joly with 380 mm focal length.

The “Full” version, for astrophotographers, can be found >> HERE <<.

Technical information :

• Object(s): NGC281 (Pacman)
• Place: Ajon (Bogève – Haute-Savoie – France)
• Date : 23th September 2011
• Constellation : Cassiopeia (Cas)
• Numerical device : Canon EOS 350D Baader
• Telescope: William Optics Megrez 110 + Televue Corrector
• Number of shots: 39
• Unit exposure time: 5 min at 200 ISO (i.e. total exposure : 3h15)
• Mounting: Losmandy G11 + Gemini
• Guiding with LVI Smartguider on a William Optics Zenithstar 66 SD + Televue Powermate 2.5x
• Pre-processing / Processing : Deep Sky Stacker, Pixinsight LE, Photoshop CS5.5

Useful link :

• NGC281/Pacman (Wikipedia)

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