Date Posted: 9/2/2025
Date Taken: Five nights, from 8/26/2014 - 10/17/2014
Scope: William Optics Megrez 90 with Televue 0.8x FR/FF, f/5.5, 496mm
Camera: QSI 583wsg with Astrodon Tru-Balance E-Series Gen2 filters
Temp: -15C
Mount: Losmandy G-11 Gemini
Guiding: Lodestar, off-axis
Exposure: LRGB 570:250:250:245; Luninance 10min unbinned, RGB 5min unbinned.
Calibrated and Stacked with CCDStack 2; RGB combine and DDP with Maxim DL; Final processing with CS4.

Messier 31, aka the Andromeda Galaxy, is the closest major galaxy to us; it is still 2.5 mly away. It was only 100 years ago that Edwin Hubble discovered a Cepheid variable in the galaxy, which allowed him to calculate its distance, and the discovery that 'spiral nebula' were in fact separate galaxies distinct from the Milky Way.

This is a two-panel mosaic taken over 5 nights; the integration times reflect combined times for both panels. I used Microsoft ICE to stitch the frames together. This is a partial re-process of an older image, to take advantage of newer tools and better processing skills.