Messier 31 is also the closest large galaxy to our own and will eventually merge with the Milky Way. M31 is one of the brightest galaxies in our skies and can be spotted with the naked eye, even from moderately dark locations.

This image was taken over three nights from a location near Elk Island park, about 45 minutes east of the city. On the light pollution map it appears as a yellow zone. So, it's not a fully dark site but still, a whole a lot better than my back yard in the city.

At the time, this was my longest run of exposures for a single image. The total exposure time was over 12 hours of which about 7 hours worth was actually useable. The sub-frames are a variety of exposures ranging from 4 to 15 minutes each.

Below is a list of the exact exposure times per filter:

• Lum: 9x4m + 5x5m = 36m + 25m = 61m
• Red: 9x4m + 5x5m = 36m + 25m = 61m
• Green: 9x4m + 5x5m = 36m + 25m = 61m
• Blue: 9x4m + 12x8m = 36m + 96m = 132m
• Ha: 6x10m + 4x15m = 60m + 60m = 120m
• Total: 435m (7hr, 15m)

This untidy set of frames was not by design. What actually happened was after each session I would process the images and see how things turned out. Then, for the next session I'd make some changes to see if it would improve things. The end result was a variety of raw frames, all of which contributed to this image.