Deep Sky
M81 & M82 - Bode's and Cigar Galaxies
Image Story
This image marked my first serious attempt at combining data from multiple nights. Until then, most of my astrophotography sessions were single-night projects, but I wanted to see what would happen if I simply kept collecting photons and trusted the process.
M81 and M82 make a fascinating pair. Although they appear close together in the sky, they are very different galaxies. M81 shows elegant spiral structure, while M82 looks distorted and chaotic, shaped by gravitational interactions with its larger neighbour.
The biggest lesson from this project was patience. Collecting data over multiple nights required resisting the urge to process early and instead waiting until enough data had accumulated. When the final stack came together, I could finally see details that had been hidden in the individual sessions. It was the moment I started to appreciate just how powerful long integration times can be.
Acquisition
| Filter | Exposure | Frames | Integration | Gain | Temperature |
|---|---|---|---|---|---|
| IR Cut | 20s | 900 | 5h | 110 | ~13–18°C |
Processing Workflow
- 1 Calibrated multiple nights with matching darks, flats and dark flats.
- 2 Combined and registered the multi-night dataset.
- 3 Stacked 900 light frames with 2x drizzle.
- 4 Applied photometric colour calibration.
- 5 Removed gradients and denoised using GraXpert.
- 6 Applied deconvolution.
- 7 Created starless and star mask versions.
- 8 Final composition, contrast and colour adjustments in Affinity Photo.