Characteristics:
Magnitude:  7.0 (open star cluster)
Size: about 35'
Distance: ?10,000 light years
RA: 0h 52m 48s
Dec: 56 degrees 37' 0"

Description:
NGC 281 is a star cluster associated with nebulosity.  The young, blue central stars are being formed from the surrounding gas, which emits in Ha as it is excited by stellar radiation.  The nebulosity of this region is faint and can be best appreciated in long exposure images such as this.  The nickname "Pacman Nebula" derives from its appearence when viewed sideways (although I prefer the above orientation). 

Photographic Details:
Date:  August 7, 2005
Scope:  Takahashi FS102 at f8, on the G11 Losmandy Mount.
Autoguider:  SBIG STV with e-finder.
Camera:  Maxcam CM10.
Filter:  Astrodon Ha filter (6 nm bandpass); Astronomik RGB type II filter set; IDAS LPS filter used for this image to suppress light pollution near the northeast horizon.
Exposures:  Ha filter, 8 x 10' each unbinned.  RGB, 25 minutes each (5 x 5'), binned 2x2.  Total exposure: 155 minutes.
Conditions:  Temperature 75 degrees F; above average transparency, below average seeing; calm; intermittent clouds.  I shot the RGB frames at the beginning of the session during relatively clear skies, but the Ha portion of imaging was limited to only 80 minutes due to clouds.
Post-processing:  This represents an Ha:HaR:G:B image.  Subs were debloomed with Ron Wodaski's Debloomer software, dark frame calibrated, and then aligned in Registar.  Sigma combined using RC Sigma Reject MaximDL, followed by DDP in ImagesPlus (IP).  Further processing in Photoshop CS (16 bit format).

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