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Wednesday, December 5, 2012
Yesterday, before the clouds rolled in, I got four hours of light emitted by the ionized hydrogen (H-alpha) for this target. I started this project back in 2010 but for some reason never finalized it. Total exposure time is now nine hours.
An emission nebula in constellation Cygnus
Sharpless 112 is an emission nebula in Cygnus at distance ~5500 light years.
Not a very bright one, there are lots of dim background nebulosity but my 7h of exposures for H-a is not enough to show it well.
Image in mapped colors from the light emitted by ionized elements.
Red=Sulfur, Green=Hydrogen and Blue=Oxygen.
Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.
Optics, Meade LX200 GPS 12" @ f5
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 8Hz
Image Scale, ~0,8 arc-seconds/pixel
21 x 1200s exposures for the H-alpha, emission of ionized Hydrogen = 7h
3 x 1200s exposures for the O-III, emission of ionized Oxygen = 1h
3 x 1200s exposures for the S-II, emission of ionized Sulfur = 1h