M51 – Whirlpool Galaxy

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M51 (NGC 5194) is a spiral galaxy in the constellation Canes Venatici (Hunting Dogs). In the image, one can see M51 interacting with the dwarf galaxy NGC 5195.

M51 - Whirlpool Galaxy in LRGB+HA

Imaging Details

  • Processing Workflow: LRGB+HA
  • Luminance: 64*60 seconds
  • Red: 69*90 seconds
  • Green: 75*90 seconds
  • Blue: 82*90 seconds
  • HA: 17*600 seconds
  • Total Imaging Time: 9.5hrs
  • Imaging Dates:
    • 4/22/2020
    • 4/29/2020
    • 5/3/2020
    • 5/11/2020

Unprocessed Images

Overall, the development of the final image used my standard LRGB+HA workflow. You can see how a single image (using the red filter), transformed into the final image when working through the entire process.

Previous Attempts

I’ve tried to image this galaxy multiple times over the course of a few years, each with varying results.

In 2013, I tried this using the Meade LX200 12 inch telescope, with the factory mount and a Canon T1i DSLR.

Picture turned out decently, especially for some of my earlier attempts at astrophotography. I was limited to 30 second exposures due to the poor tracking of the standard Meade mount. After aligning and stacking my images with Deep Sky Stacker (DSS), I used Adobe Lightroom to do my photo editing.

Five years later, I upgrade the mount to a Losmandy G11T. My camera also got a minor upgrade to a Canon T5i. I was able to take longer exposures (90 seconds).

I again used DSS and Lightroom for the photo editing. This image was better than the one taken in 2013, but I’m missing a lot of the details and brightness due to the light pollution in my area, Bortle Scale 6. At least this is what I believe.

I then upgraded my camera to a monochrome CMOS camera (ZWO ASI 1600mm) with an integrated filter wheel. I also started using PixInsight for all of my image editing.

Even though my exposure is still limited to 90 seconds, due to light pollution, the details are much better than what I was able to get in 2017 due to a better camera and better software specifically designed for astrophotography.

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