M13 — Hercules Cluster
The finest globular cluster in the northern sky, a dense ball of several hundred thousand stars in the constellation Hercules.
View photos ↓- Object type
- Globular cluster
- Constellation
- Hercules
- Designation
- M13 (NGC 6205)
- Distance
- ≈ 22,200 light-years
- Apparent magnitude
- 5.8
- Apparent size
- 20 arcmin
- Best season
- Spring / Summer (best visibility May to August)
The Hercules Cluster (M13) is considered the finest globular cluster visible from the northern hemisphere. It packs several hundred thousand stars into a sphere roughly 145 light-years across, so densely that its core remains impossible to resolve into individual stars with amateur equipment.
In this image, stars stand out clearly around the edges of the cluster and grow progressively denser toward the center, eventually merging into a continuous glow where the sensor’s resolution can no longer separate them.
Session shot with the Seestar S30 Pro mounted in equatorial mode on the EQ3, the same night as the Pelican Nebula: 110 sub-exposures of 10 seconds each (≈ 18 minutes total integration), stacked and processed in Siril.
