My primary target of the night, the Trifid Nebula, set around 2 AM. I just wasn't happy with the few subs of the Propeller I got on the 22nd, so I decided to use the rest of the night to pick up a few more. I set an alarm for 2 AM and got up to move the scope to the Propeller. Synched on Sadr and used the PicGoto to go to the Propeller coordinates. I was a little off, but could see the asterisms I wanted in my guide scope so used that to get on target. Attempted to get closer to balance rather than blatantly weighting one side, and I think the guiding was a little better. I used unidirectional DEC again. This image combines my 22 Jul 2015 data with the data I took tonight (morning of 25 Jul 2015). It is certainly less noisy. I have processed this much more extensively than my 22 Jul image, trying to bring out the propeller and detail within it. I’ll next use this for an HαRRGB combination.
Date: 22, 25 Jul 2015
Subject: DWB111, Propeller Nebula
Scope: Astrotech AT8IN+Antares 0.5x focal reducer
Filter: Baader 7 nm Hα
Mount: CG-5 (Synta motors, PicGoto Simplificado)
Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.5.0.1 (Win 7 ASCOM)
Camera: DSI IIc no cooling (about 24 °C)
Acquisition: Nebulosity 4.0.2, no dither
Exposure: 12+14x600 s
Stacking: Neb 4.0.2, bad pixel map, bias included, 33 flats, OSC extract R, normalize intensities, square, align. DSS 2x drizzle, 1.5σ median κ-σ stack.
Processing: StarTools 1.3.5.289 Crop; Develop: 75.81%; HDR
ptimize; Deconvolute 6.0 pix (heavily masked so sharpening only happens in selected regions); Track 4.5 pix, smoothness 79%; Magic, shrink 2 pix. Photoshop CC 2014 + Carboni Astronomy Tools layer masked Local contrast enhance; curves; Astroframe.
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