Deep Sky
M13 - Hercules Cluster
Image Story
The Hercules Cluster is one of the most impressive objects visible through a small telescope. Even visually, it stands out as a dense swarm of stars suspended in space.
Photographing it turned out to be more challenging than I expected. The bright core can easily become overexposed, causing thousands of stars to blend together into a featureless glow. To preserve detail, I combined exposures of different lengths so the centre would remain resolved.
What fascinates me about M13 is its scale. The cluster contains hundreds of thousands of stars packed into a relatively small region of space. Looking at the final image, almost every point of light belongs to the cluster itself rather than the foreground stars of our own neighbourhood.
It is one of those objects that reminds me just how crowded parts of our galaxy can be compared to the space around our Sun.
Acquisition
| Filter | Exposure | Frames | Integration | Gain |
|---|---|---|---|---|
| IR Cut | 10s | 150 | 25m | 110 |
| IR Cut | 5s | 50 | 4m 10s | 110 |
Processing Workflow
- 1 Calibrated with darks and flats.
- 2 Stacked 10s and 5s exposures separately.
- 3 Combined integrations to preserve detail in the cluster core.
- 4 Applied photometric colour calibration.
- 5 Removed gradients using GraXpert.
- 6 Stretched the image.
- 7 Final scaling, contrast and colour adjustments.