M68
NGC 4590 · Globular cluster in Hydra
- Magnitude
- 7.8
- Size
- 11′
- Effective surface brightness
- 21.4 mag/arcsec²
- Best months
- Mar, Apr, May
- Declination
- -27°
- Filter
- None (broadband target)
A loose globular in Hydra, low from the UK but easy from lower latitudes.
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 | 26% | 14 min84 subs | 21 min126 subs | 52 min313 subs |
| ZWO Seestar S50 Pro10 s subs | 13% | 15 min93 subs | 23 min139 subs | 57 min340 subs |
| ZWO Seestar S3010 s subs | 15% | 15 min93 subs | 22 min135 subs | 53 min321 subs |
| ZWO Seestar S30 Pro10 s subs | 8% | 16 min99 subs | 25 min148 subs | 1 h359 subs |
| DwarfLab DWARF 315 s subs | 11% | 19 min76 subs | 30 min120 subs | 1 h 18 min311 subs |
| DwarfLab DWARF mini15 s subs | 15% | 14 min56 subs | 21 min84 subs | 52 min208 subs |
| DwarfLab Draco30 s subs | 15% | 15 min30 subs | 17 min35 subs | 43 min86 subs |
| DwarfLab DWARF II15 s subs | 10% | 57 min230 subs | 1 h 17 min308 subs | 2 h 43 min653 subs |
| Vaonis Vespera II10 s subs | 13% | 14 min84 subs | 21 min126 subs | 52 min313 subs |
| Vaonis Vespera Pro10 s subs | 11% | 33 min200 subs | 48 min289 subs | 1 h 53 min680 subs |
| Vaonis Vespera 310 s subs | 13% | 13 min80 subs | 20 min121 subs | 50 min299 subs |
| Vaonis Vespera Pro 210 s subs | 11% | 31 min189 subs | 46 min275 subs | 1 h 48 min651 subs |
| Unistellar eQuinox 24 s subs | 32% | 17 min254 subs | 21 min320 subs | 41 min610 subs |
| Unistellar Odyssey4 s subs | 33% | 1 h 27 min1,312 subs | 1 h 44 min1,553 subs | 2 h 54 min2,608 subs |
| Celestron Origin10 s subs | 21% | 5 min30 subs | 5 min33 subs | 14 min86 subs |
| Celestron Origin Mark II10 s subs | 25% | 5 min30 subs | 7 min44 subs | 20 min120 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 M68 with the ZWO Seestar S50
- How long to image the M68 with the ZWO Seestar S50 Pro
- How long to image the M68 with the ZWO Seestar S30
- How long to image the M68 with the ZWO Seestar S30 Pro
- How long to image the M68 with the DwarfLab DWARF 3
- How long to image the M68 with the DwarfLab DWARF mini
- How long to image the M68 with the DwarfLab Draco
- How long to image the M68 with the DwarfLab DWARF II
- How long to image the M68 with the Vaonis Vespera II
- How long to image the M68 with the Vaonis Vespera Pro
- How long to image the M68 with the Vaonis Vespera 3
- How long to image the M68 with the Vaonis Vespera Pro 2
- How long to image the M68 with the Unistellar eQuinox 2
- How long to image the M68 with the Unistellar Odyssey
- How long to image the M68 with the Celestron Origin
- How long to image the M68 with the Celestron Origin Mark II