RCOS Ritchey-Chretien scope at f/9  with ST-10XME CCD camera at -15 °C on the 

  A-P 1200 GTO  mount.   Guided with ST-4 on separate guide scope. SBIG CFW-8 filter wheel and Astrodon filters.         

 Ten 5 min exposures L, R, G, and B, all at 1x1 binning.

 Raw frames were dark and flat-field calibrated and rgb color combined in MaxIm 4.10. 

  The luminance image was then registered with the RGB image in RegiStar. The images were imported into Photoshop and 

  combined with the L image as Luminosity at 100% opacity. The RGB and luminosity layers were then separately adjusted

  with Levels and Curves before flattening and converting to a jpg file.