Hercules Cluster
M13, NGC 6205 · Globular cluster in Hercules
- Magnitude
- 5.8
- Size
- 20′
- Effective surface brightness
- 20.7 mag/arcsec²
- Best months
- May, Jun, Jul
- Declination
- +36°
- Filter
- None (broadband target)
The great northern globular, a few hundred thousand stars in a ball a third the Moon's width. Quick and always satisfying.
Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
How long with each smart telescope
| Telescope | In frame | Bortle 3 (rural) | Bortle 5 (suburban) | Bortle 7 (urban edge) |
|---|---|---|---|---|
| ZWO Seestar S5010 s subs | 46% | 5 min30 subs | 5 min32 subs | 11 min69 subs |
| ZWO Seestar S50 Pro10 s subs | 24% | 5 min30 subs | 6 min35 subs | 12 min75 subs |
| ZWO Seestar S3010 s subs | 28% | 5 min30 subs | 5 min33 subs | 12 min71 subs |
| ZWO Seestar S30 Pro10 s subs | 15% | 5 min30 subs | 6 min37 subs | 13 min79 subs |
| DwarfLab DWARF 315 s subs | 20% | 8 min30 subs | 8 min30 subs | 17 min69 subs |
| DwarfLab DWARF mini15 s subs | 28% | 8 min30 subs | 8 min30 subs | 11 min46 subs |
| DwarfLab Draco30 s subs | 27% | 15 min30 subs | 15 min30 subs | 15 min30 subs |
| DwarfLab DWARF II15 s subs | 19% | 14 min57 subs | 18 min73 subs | 35 min142 subs |
| Vaonis Vespera II10 s subs | 23% | 5 min30 subs | 5 min32 subs | 11 min69 subs |
| Vaonis Vespera Pro10 s subs | 21% | 9 min53 subs | 12 min71 subs | 25 min149 subs |
| Vaonis Vespera 310 s subs | 23% | 5 min30 subs | 5 min30 subs | 11 min66 subs |
| Vaonis Vespera Pro 210 s subs | 20% | 8 min50 subs | 11 min67 subs | 24 min143 subs |
| Unistellar eQuinox 24 s subs | 58% | 4 min60 subs | 5 min74 subs | 9 min132 subs |
| Unistellar Odyssey4 s subs | 59% | 20 min297 subs | 23 min346 subs | 37 min558 subs |
| Celestron Origin10 s subs | 39% | 5 min30 subs | 5 min30 subs | 5 min30 subs |
| Celestron Origin Mark II10 s subs | 45% | 5 min30 subs | 5 min30 subs | 5 min30 subs |
Imaging the globular cluster
Globular clusters are point sources packed tight, so they come quickly: the core resolves into stars within a handful of minutes on any smart scope. More time deepens the halo and pulls in the faint outer members. Use short subs so the core does not saturate into a white blob, and no filter.
Per-telescope pages
- How long to image the Hercules Cluster with the ZWO Seestar S50
- How long to image the Hercules Cluster with the ZWO Seestar S50 Pro
- How long to image the Hercules Cluster with the ZWO Seestar S30
- How long to image the Hercules Cluster with the ZWO Seestar S30 Pro
- How long to image the Hercules Cluster with the DwarfLab DWARF 3
- How long to image the Hercules Cluster with the DwarfLab DWARF mini
- How long to image the Hercules Cluster with the DwarfLab Draco
- How long to image the Hercules Cluster with the DwarfLab DWARF II
- How long to image the Hercules Cluster with the Vaonis Vespera II
- How long to image the Hercules Cluster with the Vaonis Vespera Pro
- How long to image the Hercules Cluster with the Vaonis Vespera 3
- How long to image the Hercules Cluster with the Vaonis Vespera Pro 2
- How long to image the Hercules Cluster with the Unistellar eQuinox 2
- How long to image the Hercules Cluster with the Unistellar Odyssey
- How long to image the Hercules Cluster with the Celestron Origin
- How long to image the Hercules Cluster with the Celestron Origin Mark II