Instrument

12.5" RCOS @  ~f/9 (2880 mm fl) 0.64 arcsec / pixel.  The Zoomify image scale is 0.85 to 2.72 arcsec / pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ internal filter wheel, AstroDon Gen I Filters

Acquisition Data

9/4/2010 to 11/12/2010 Chino Valley, AZ... with CCDAutoPilot3 & CCDSoft.  AOL guided

Exposure

Lum (no filter)  420 min (28 x 15 min, bin 1x1)

Ha                 600 min (20 x 30 min, bin 1x1)

RGB                225 min ( 5 x 15 min each, bin 2x2)

Software

• CCDSoft, CCDStack, Photoshop CS w/ the Fits Liberator plugin, Noel Carboni's actions and and Russell Croman's GradientXTerminator.

• eXcalibrator for (b-v), (v-r) color calibration, using 32 stars from the NOMAD1 database... plus a small adjustment to the yellow, by Terry Tuggle.

• PixFix32 (pre-beta) to repair column defects.

• CCDStack to calibrate, register, normalize, data reject,  combining the sub exposures and LRGB combine

• PhotoShop for non-linear stretching, LLRGB combine.

North is ~ to the top, the image is rotated 10° clockwise.

IC 342, The Hidden Galaxy, is located in the constellation Camelopardalis, at a distance of about 10.2 million light-years. Because of its close proximity to the galactic plane, IC 342 remained hidden until the relatively recent discovery date of 1895, by W.F. Denning.

Much like viewing the Sun at sunset, galactic extinction shifts the color of IC 342 towards the red. The blue light is reduced by magnitude 2.4, the green 1.85 and the red by 1.49. Without the galactic extinction, IC 342 would have the blue and white color commonly seen in spiral galaxies and would be bright enough to spot with binoculars..