Returning to the Sculptor Galaxy

I finally got a good night to revisit one of my favorite targets, the Sculptor Galaxy. It is pretty low in my southern sky, but a beautiful, bright object as galaxies go, so it was one I tried early in my foray into astrophotography and one where I like to return. I missed it last year because the tracking controls of my mount were broken, but this year I want to try out my newly-learned skills and improved PicGoto mount control. 

Conditions were better than average with just a slight bit of wind.  I got a late start because I did the Chemistry Magic show earlier in the evening, but it wouldn't have made a lot of difference because NGC 253 doesn't rise over the mountain until around my starting time anyway. I synched from Diphda (β Cet) and the PicGoto was right on. With as much Dec backlash as my mount has, it is amazing to me how well the PicGoto always seems to do. I used a developer build of PHD2 (2.3.1k, I believe) and it seems to be unstable. More than once last night I got calibrated, started guiding, stopped to reframe the image, then had PHD2 (my guiding software) crash when I tried to start looping again. So I had to start over and recalibrate two or three times and didn't get imaging started until about 10:30 PM. I think I'm going to go back to the last stable release build of PHD2 and see if these problems are due to the build or to all the other software changes I've made. This image needs some flats (I need to remove several dust bunnies), which I can probably get tonight (I left for work before dawn this morning!).

Here's the picture. I still think this is one of the most beautiful galaxies out there, and this is my best image of it so far.

Date: 22 Oct 2014

Subject: NGC 253, Sculptor Galaxy

Scope: AT8IN

Filter: Baader Fringe Killer

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

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

Camera: DSI IIc chiller at 2.50 A, 5-7 °C

Acquisition: Nebulosity 3.2.1, no dither

Exposure: 45x300 s

Stacking: Neb 3, bad pixel map, bias included, no flats, normalize, trans+rot align, 1.5 SD stack.

Processing: StarTools 1.3.5.289 Crop; Wipe:Color & brightness 78%; Develop 79.3%; HDR:Optimize; Deconvolute auto mask 3.0 pix; Color:Scientific, 300%; Track Grain size 3.0 pix; Magic:Shrink 1 pix (twice). Photoshop CC 2014 + Carboni Astronomy Tools Increase star color; Levels (darken) with a layer mask to take out some dust bunnies; Astro Frame.