This is one of those "don't image from the suburbs, LRGB methods are essential" type objects that I'm crazy enough to try anyway. I do like going after something new every once in a while, and this is a new object for me. Consider it a “challenge” object. Synched from β Tri and found on the first attempt. Some wind gusts & some scattered clouds, but conditions overall were very good. NGC 925 is quite dim, especially the spiral arms (the core is reasonably bright so not terrible to find at 5 s exposures or so). Chose the UHC-S filter, hoping to improve contrast between the galaxy and background sky glow. Used 600 s exposures for the imaging session. Got fairly good data all the way up to the meridian, and finally the mount bumped about 4 AM, ending the session.
Date: 25 Sep 2014
Subject: NGC 925
Scope: AT8IN
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, 18-11 °C
Acquisition: Nebulosity 3.2.1, no dither
Exposure: 40x600 s
Stacking: Neb 3, bad pixel map, bias included, no flats, OSC neb filter extract, normalize, trans+rot align, 1.5 SD stack.
Processing: StarTools 1.3.5.289 Crop; Wipe:Color & brightness 75%; Develop 87.49%; HDR
ptimize; Color:Scientific, 250%; Life:Moderate; Deconvolute auto mask 2.9 pix; Track Grain size 9.1 pix, Scl 1 100%, Scl 2 100%, Scl 3 96%; Magic:Shrink 1 pix (twice). Photoshop CC 2014 + Carboni Astronomy Tools Healing brush; Deep space noise reduction; Levels (darken); Increase star color; Astro Frame.
Comments