Imaging telescopes or lenses: Astro-Tech AT8IN
Imaging cameras: ZWO ASI1600MM-Cool
Mounts: Skywatcher NEQ-6 Pro Synscan
Guiding telescopes or lenses: Astro-Tech AT8IN
Guiding cameras: ZWO AS120MM-Mini
Focal reducers: High Point Scientific Coma Corrector Photo & Visual For Netwonian Telescopes 2"
Software: Microsoft Image Composite Editor (ICE) · DeepSkyStacker · Silicon Fields StarTools 1.3 · Noel Carboni's Astro Tools for PhotoShop · AstroPlanner · PHD2 Guiding · Sequence Generator Pro · EQASCOM · photoshop
Filters: ZWO Red 31 mm · ZWO Luminance 31 mm · ZWO Green 31 mm · ZWO Blue 31 mm
Accessory: Orion Thin Off Axis Guider (TOAG) · Robert Brown's Arduino ASCOM Focuser Pro DIY · ZWO EFW filter wheel
Dates:Nov. 6, 2019 , Nov. 7, 2019
Frames:
ZWO Blue 31 mm: 60x120" (gain: 139.00) -20C bin 1x1
ZWO Green 31 mm: 75x120" (gain: 139.00) -20C bin 1x1
ZWO Luminance 31 mm: 120x180" (gain: 139.00) -20C bin 1x1
ZWO Red 31 mm: 75x120" (gain: 139.00) -20C bin 1x1
Integration: 13.0 hours
Avg. Moon age: 9.67 days
Avg. Moon phase: 73.32%
Bortle Dark-Sky Scale: 5.00
Astrometry.net job: 3053245
RA center: 0h 42' 43"
DEC center: +41° 16' 20"
Pixel scale: 1.720 arcsec/pixel
Orientation: 2.064 degrees
Field radius: 1.419 degrees
Resolution: 3973x4416
Locations: Mapleton Lateral Observatory, Mapleton, Utah, United States
Data source: Backyard
2.54 ± 0.11 MLy
Here’s my 2019 attempt at M31. This is a 6-panel mosaic. Acquisition was plagued with focuser problems (because the tension was set incorrectly, it refused to move both directions so ultimately I disabled autofocusing, focused once, and went to bed). The results were so bad I threw out about half the data from the first night. Another result was there were no usable B subs for the bottom-left panel; I used synthetic blue (created in StarTools by channel interpolation) there. Nevertheless, in the end I think this image blows all my previous attempts on this very-often-imaged target out of the water. As is always the case, it would benefit from more integration time but it just takes a lot of time to get more when there are 6 panels! I know this is nothing for many of you, but this is my first try for a multi-panel image with LRGB techniques.
Date: 7-9 Nov 2019
Subject: M31, Andromeda Galaxy
Scope: AT8IN+High Point Scientific Coma Corrector
Filters: ZWO 31 mm diameter unmounted LRGB
Mount: EQ-6 (EQMOD 2.000j)+PEC
Guiding: Orion Thin Off-axis Guider + ASI120MM-mini +PHD 2.6.6 (Win 10 ASCOM)
Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21
Acquisition: Sequence Generator Pro 3.1.0.345
Exposure: 6 panels, each 20x180 L, 15x120 R, 15x120 G, 15x120 B
Stacking: Deep Sky Stacker 4.2.2 (64-bit) dark+flat+bias, κ-σ stacking with κ = 1.5.
Processing: StarTools 1.6.380: For each panel, combined L, R, G, & B in StarTools, using correct exposure times to add synthetic luminance from R, G, & B. Software binned 2x2, cropped, wiped, developed ~90 %, HDR optimized (combination of “hard” and “reveal all”), used the color module with significant saturation boosting, deconvoluted, and untrack denoised. Rotated a few panels 180° to get proper relative orientation. Stitched all panels together using Microsoft Image Composite Editor. Deep space noise reduction in Photoshop, with a little attempt to mess with the color in the bottom left part of the image using a layer mask. Slight levels adjustment, followed by AstroFrame.
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