I'm not satisfied with my M31s so far, so I'm trying again on what is one of my oldest deep sky targets. I'm trying a 2-panel mosaic of Andromeda Galaxy. Conditions are excellent: cool, clear, and calm. Chiller at 2.5 A, 4.5 °C. My guide scope is still out of focus; I must not have fully inserted the camera. I plan to do the north end of the galaxy as I image up to the meridian, then I'll do a flip and move to image the south end. Fixed the guider focus issue after the meridian flip. Guiding, for the moment at least, is improved. Excellent performance all the way until dawn. This target is deceptively difficult because of its size and very high dynamic range. I think the bottom and top of the mosaic still don’t match up very well. I could spend a lot more time trying to process this better, and probably will, but I think this is my best Andromeda so far.

Extensively reprocessed in the revision. Some of the chief changes were more deconvolution to bring out detail and lots of layer mask work to keep the overexposed portions from standing out too sharply and to darken the background sky.

Date: 2 Oct 2014

Subject: M31, Great Andromeda Galaxy

Scope: Orion ST-80 + Antares 0.5x telereducer

Filter: Baader UHC-S

Mount: CG-5 (Synta motors, PicGoto Simplificado)

Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.3.1 (Win 7 ASCOM)

Camera: DSI IIc chiller at 2.50 A, 4 to 2 °C

Acquisition: Nebulosity 3.2.1, no dither

Exposure: Upper, 49x300 s, Lower, 57x300 s

Stacking: Neb 3, bad pixel map, bias included, no flats, OSC nebula filter extract, normalize, debayer and square, trans+rot align, 1.5 SD stack.

Processing: (attempting to do the same thing to upper and lower frames) StarTools 1.3.5.289 Crop; Develop 87.49%; Color: scientific, 250%; Deconvolute 2.0 pix; Life:Less=more; Track Grain size 7.2 pix, Smoothness 70%; Magic:Shrink 1 pix. Photoshop CC 2014 + Carboni Astronomy Tools Healing brush; Photomerge; Levels; Star color enhance (twice); Increase local contrast; Astro Frame.