Instrument

12.5" RCOS @  ~f/9 (2897 mm fl) 0.64 arcsec / pixel.  The Zoomify image scale is 0.64 to 3.42 arcsec / pixel.

Mount

Paramount ME

Camera

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

Acquisition Data

4/5/2011 to 5/7/2011 Chino Valley, AZ... with CCDAutoPilot3 & CCDSoft.  AOL guided

Exposure

Lum 510 min (34 x 15 min, bin 1x1 (best of 56)

RGB 675 min (15 x 15 min each, bin 2x2)

Software & Processing

CCDSoft, CCDStack, Photoshop CS3, Noel Carboni's actions and Russell Croman's GradientXTerminator.

The color was balanced by setting the sum of NGC 5985's light to white. This is a reasonable assumption as these galaxies are relatively close and there is very little foreground galactic extinction. In this case, eXcalibrator's color balance does not look correct, but maybe it is.

PixFix32 (pre-beta) to repair column defects.

CCDStack to calibrate, register, normalize, data reject,  combine the sub exposures, Selective deconvolution and LRGB combine.

PhotoShop for non-linear stretching and LLRGB combine.

Noiseware Pro, a PhotoShop plug-in.

North is to the top.

This beautiful trio of galaxies is located in the constellation Draco. From left to right are face-on spiral NGC 5985, elliptical galaxy NGC 5982, and edge-on spiral NGC 5981. Their respective distances are about 114, 137 and 80 million light-years.