top of page

Messier 109 - Galaxy Astrophotography in Mono LRGB

Updated: May 22, 2023

Messier 109 is a barred spiral galaxy located in the constellation of the big bear, Ursa Major. It was discovered by Pierre Méchain in the year 1781. Messier 109 occupies the second to last entry in Messier's famous catalog of deep sky objects, in between M108 (seen edge-on and photographed during Episode 12 with M97) and M31's satellite galaxy M110 photographed in Episode 4 of Galactic Hunter.

M109 looks small and is not super bright at magnitude 11. It is part of the M109 group, a group of 79 galaxies of which it is the brightest member.

Below is our image of Messier 109. We consider this an unsuccessful attempt as we are not happy with our final image and will definitely try to get a better result another time.

This was taken soon after switching from our Canon 7D Mark II DSLR camera to our ASI 1600MM cooled Astrophotography camera, and we had no idea what settings to use for this object. More info on that is below!

We've tried to process our files several times, and you will see further down this post a version of M109 with a much smoother, less brutal processing workflow.

3 hours and 54 minutes on M109

Spiral Barred Galaxy Messier 109 photographed using a ZWO ASI 1600MM CMOS camera for Astrophotography and an 8" Orion telescope Astrograph f/3.9


Acquisition: ASIAIR

Processing: Pixinsight


Total Exposure Time: 3 hours and 54 minutes

Exposure Time per frame: 3 minutes

Filters: L (1 hour) / R (1 hour) / G (1 hour) / B (54 min)

Gain: 139


How to Locate Messier 109