Deep Sky
M51 - Whirlpool Galaxy
Image Story
The Whirlpool Galaxy is one of those classic astrophotography targets that every deep-sky imager eventually wants to capture. Its bright spiral arms and interacting companion galaxy make it instantly recognisable, even to people who are not familiar with astronomy.
This image represents a turning point in my processing journey. By this stage I had become more comfortable combining multiple sessions and experimenting with more advanced workflows. Rather than simply stretching the image and calling it done, I spent time working on colour balance, star separation and detail enhancement to bring out the structure hidden within the data.
What I enjoy most about M51 is that it genuinely looks like a galaxy. Even from tens of millions of light-years away, the spiral arms remain clearly visible. Every time I look at it, I am reminded that the faint smudge captured by a small telescope is actually an entire island universe containing billions of stars.
Acquisition
| Filter | Exposure | Frames | Integration | Gain |
|---|---|---|---|---|
| IR Cut | 20s | 519 | 2h 53m | 110 |
Processing Workflow
- 1 Calibrated multiple sessions with matching darks, flats and dark flats.
- 2 Registered and stacked the multi-session dataset in Siril via Sirilic.
- 3 Cropped stacking artifacts and image borders.
- 4 Removed gradients and neutralized the background.
- 5 Applied colour calibration and white balance.
- 6 Corrected aberrations and enhanced detail using Cosmic Clarity.
- 7 Generated starless and star mask layers.
- 8 Performed statistical and hyperbolic stretching on the starless image.
- 9 Recombined stars with the processed starless image.
- 10 Final colour and presentation adjustments in Affinity Photo.