M28
NGC 6626 · Globular cluster in Sagittarius
- Magnitude
- 6.8
- Size
- 11′
- Effective surface brightness
- 20.4 mag/arcsec²
- Best months
- Jun, Jul, Aug
- Declination
- -25°
- Filter
- None (broadband target)
A compact globular near Lambda Sagittarii, a degree from M22. Small and quick.
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% | 5 min30 subs | 5 min30 subs | 9 min57 subs |
| ZWO Seestar S50 Pro10 s subs | 13% | 5 min30 subs | 5 min31 subs | 10 min62 subs |
| ZWO Seestar S3010 s subs | 15% | 5 min30 subs | 5 min30 subs | 10 min59 subs |
| ZWO Seestar S30 Pro10 s subs | 8% | 5 min30 subs | 5 min32 subs | 11 min66 subs |
| DwarfLab DWARF 315 s subs | 11% | 8 min30 subs | 8 min30 subs | 14 min57 subs |
| DwarfLab DWARF mini15 s subs | 15% | 8 min30 subs | 8 min30 subs | 9 min38 subs |
| DwarfLab Draco30 s subs | 15% | 15 min30 subs | 15 min30 subs | 15 min30 subs |
| DwarfLab DWARF II15 s subs | 10% | 13 min51 subs | 16 min63 subs | 29 min118 subs |
| Vaonis Vespera II10 s subs | 13% | 5 min30 subs | 5 min30 subs | 9 min57 subs |
| Vaonis Vespera Pro10 s subs | 11% | 8 min48 subs | 10 min62 subs | 21 min124 subs |
| Vaonis Vespera 310 s subs | 13% | 5 min30 subs | 5 min30 subs | 9 min55 subs |
| Vaonis Vespera Pro 210 s subs | 11% | 7 min45 subs | 10 min59 subs | 20 min119 subs |
| Unistellar eQuinox 24 s subs | 32% | 3 min52 subs | 4 min63 subs | 7 min109 subs |
| Unistellar Odyssey4 s subs | 33% | 17 min251 subs | 19 min289 subs | 30 min456 subs |
| Celestron Origin10 s subs | 21% | 5 min30 subs | 5 min30 subs | 5 min30 subs |
| Celestron Origin Mark II10 s subs | 25% | 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 M28 with the ZWO Seestar S50
- How long to image the M28 with the ZWO Seestar S50 Pro
- How long to image the M28 with the ZWO Seestar S30
- How long to image the M28 with the ZWO Seestar S30 Pro
- How long to image the M28 with the DwarfLab DWARF 3
- How long to image the M28 with the DwarfLab DWARF mini
- How long to image the M28 with the DwarfLab Draco
- How long to image the M28 with the DwarfLab DWARF II
- How long to image the M28 with the Vaonis Vespera II
- How long to image the M28 with the Vaonis Vespera Pro
- How long to image the M28 with the Vaonis Vespera 3
- How long to image the M28 with the Vaonis Vespera Pro 2
- How long to image the M28 with the Unistellar eQuinox 2
- How long to image the M28 with the Unistellar Odyssey
- How long to image the M28 with the Celestron Origin
- How long to image the M28 with the Celestron Origin Mark II