Hemisphere:  Northern  ·  Contains:  Andromeda galaxy  ·  Great Nebula in Andromeda  ·  M 110  ·  M 31  ·  M 32  ·  M110  ·  M31  ·  M32  ·  NGC 205  ·  NGC 221  ·  NGC 224  ·  NGC206
Getting plate-solving status, please wait...
M31, Great Andromeda Galaxy, LRGB 6-panel mosaic, Nov. 2019, 


            David Dearden
Powered byPixInsight

M31, Great Andromeda Galaxy, LRGB 6-panel mosaic, Nov. 2019

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, 2019Nov. 7, 2019

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
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.



David Dearden
License: None (All rights reserved)

Sky plot

Sky plot


M31, Great Andromeda Galaxy, LRGB 6-panel mosaic, Nov. 2019, 


            David Dearden