M9
NGC 6333 · Globular cluster in Ophiuchus
- Magnitude
- 7.7
- Size
- 12′
- Effective surface brightness
- 21.5 mag/arcsec²
- Best months
- May, Jun, Jul
- Declination
- -19°
- Filter
- None (broadband target)
A small globular near the galactic centre, slightly dimmed by dust. Compact and easy.
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 | 28% | 15 min88 subs | 22 min134 subs | 56 min335 subs |
| ZWO Seestar S50 Pro10 s subs | 14% | 16 min97 subs | 24 min147 subs | 1 h 01 min364 subs |
| ZWO Seestar S3010 s subs | 17% | 16 min97 subs | 24 min143 subs | 57 min344 subs |
| ZWO Seestar S30 Pro10 s subs | 9% | 17 min104 subs | 26 min156 subs | 1 h 04 min385 subs |
| DwarfLab DWARF 315 s subs | 12% | 20 min79 subs | 31 min126 subs | 1 h 23 min333 subs |
| DwarfLab DWARF mini15 s subs | 17% | 14 min58 subs | 22 min89 subs | 56 min223 subs |
| DwarfLab Draco30 s subs | 16% | 15 min30 subs | 18 min37 subs | 46 min93 subs |
| DwarfLab DWARF II15 s subs | 11% | 1 h 01 min243 subs | 1 h 22 min328 subs | 2 h 55 min700 subs |
| Vaonis Vespera II10 s subs | 14% | 15 min88 subs | 22 min134 subs | 56 min335 subs |
| Vaonis Vespera Pro10 s subs | 12% | 35 min210 subs | 51 min307 subs | 2 h 01 min729 subs |
| Vaonis Vespera 310 s subs | 14% | 14 min83 subs | 21 min128 subs | 53 min321 subs |
| Vaonis Vespera Pro 210 s subs | 12% | 33 min199 subs | 48 min291 subs | 1 h 56 min697 subs |
| Unistellar eQuinox 24 s subs | 35% | 18 min270 subs | 23 min342 subs | 44 min655 subs |
| Unistellar Odyssey4 s subs | 36% | 1 h 33 min1,402 subs | 1 h 51 min1,662 subs | 3 h 07 min2,801 subs |
| Celestron Origin10 s subs | 23% | 5 min30 subs | 6 min35 subs | 15 min92 subs |
| Celestron Origin Mark II10 s subs | 27% | 5 min30 subs | 8 min46 subs | 21 min129 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 M9 with the ZWO Seestar S50
- How long to image the M9 with the ZWO Seestar S50 Pro
- How long to image the M9 with the ZWO Seestar S30
- How long to image the M9 with the ZWO Seestar S30 Pro
- How long to image the M9 with the DwarfLab DWARF 3
- How long to image the M9 with the DwarfLab DWARF mini
- How long to image the M9 with the DwarfLab Draco
- How long to image the M9 with the DwarfLab DWARF II
- How long to image the M9 with the Vaonis Vespera II
- How long to image the M9 with the Vaonis Vespera Pro
- How long to image the M9 with the Vaonis Vespera 3
- How long to image the M9 with the Vaonis Vespera Pro 2
- How long to image the M9 with the Unistellar eQuinox 2
- How long to image the M9 with the Unistellar Odyssey
- How long to image the M9 with the Celestron Origin
- How long to image the M9 with the Celestron Origin Mark II