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Messier 51 or M51 or Whirlpool Galaxy. Telescope: RRRT (Fan Mountain) Camera: SBIG STX-16803 Exposure: Red: 14 @ 2 min Blue: 14 @ 2 min Visible: 14 @ 2 min Total - 84 minutes exposure

Messier 51 On The RRRT [Whirlpool Galaxy]

Remember my last article? You know the one about my experience at the Fan Mountain Observatory in April 2019. The outcome was to target Messier 51 or the Whirlpool Galaxy with the RRRT (Rapid Response Robotic Telescope). Well the results are in and before I get there I’m going to tell you a little about the process.

24 Inch RRRT at Fan Mountain used to capture Messier 51
24 Inch RRRT (Rapid Response Robotic Telescope) at Fan Mountain

Planning Phase

Dr. Edward Murphy suggested capturing Messier 51, so I didn’t change that part of the plan. It was everything else that needed to be thought out. With the limited time available, I could choose to do a long session in visible light or break up into 3 sessions in RGB (Red/Green/Blue). And after careful consideration, I decided to challenge myself and go RGB.

Next the telescope is capable of 6 minute exposures and the most I’ve done is 30 seconds. So I baby stepped it at 2 minutes per exposure. That’s pretty much it although I had to learn new post processing tricks to put it all together.

About Messier 51

M51 Whirlpool Galaxy_RRRT
Messier 51 or M51 or Whirlpool Galaxy.

Discovered and catalogued by Charles Messier in 1773. To him it was a fuzzy nebula. Later it became the first galaxy to be classified as a spiral galaxy thanks to Edwin Hubble. Looking at the photo, you see a companion galaxy. In addition, it is a dwarf galaxy named NGC 5195. It looks to be a meal for Messier 51. Light from this group takes approximately 23 million light years to get to us. Unless you can bend space and time, visiting during your lifetime is well…impossible.


I liked most was the post processing workflow I developed. After stacking, I had to learn how to combine each color into one picture using Gimp. Check out the workflow below to see how much fun this was for me. I look forward to my next challenge as always and for you…clear skies!


  • Deep Sky Stacker: Stack each color set
  • Gimp: Merge into 1 picture.
  • Startools: Autodev, Crop, Wipe, Autodev, Deconvolution, Color, Noise reduction
  • Gimp: Final Curves adjustment, add signature

Kevin Francis

Kevin Francis is a Mechanical Engineer by day, amateur Astrophotographer by night who is taking his Google Pixel smartphone camera to new limits.