How long to image the M9 with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 2 h 17 min (2,054 subs of 4 s) for a solid image of the M9. A quick look takes 34 min; a showpiece 9 h 08 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 33 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 36% of the frame’s short side.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 22 min335 subs | 1 h 29 min1,338 subs | 5 h 57 min5,350 subs |
| Bortle 2Typical dark site | 23 min340 subs | 1 h 31 min1,360 subs | 6 h 03 min5,438 subs |
| Bortle 3Rural | 23 min351 subs | 1 h 33 min1,402 subs | 6 h 14 min5,605 subs |
| Bortle 4Rural / suburban transition | 25 min376 subs | 1 h 40 min1,502 subs | 6 h 40 min6,008 subs |
| Bortle 5Suburban | 28 min416 subs | 1 h 51 min1,662 subs | 7 h 23 min6,647 subs |
| Bortle 6Bright suburban | 34 min514 subs | 2 h 17 min2,054 subs | 9 h 08 min8,215 subs |
| Bortle 7Suburban / urban transition | 47 min701 subs | 3 h 07 min2,801 subs | 12 h11,203 subs |
| Bortle 8City | 1 h 06 min991 subs | 4 h 24 min3,961 subs | 18 h15,843 subs |
| Bortle 9Inner city | 1 h 47 min1,609 subs | 7 h 09 min6,435 subs | 29 h25,738 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 58 min of run time. The Odyssey’s battery (rated about 5 h) should cover it; a power bank still keeps the phone running the app alive. (Bortle 6, solid image; we allow 30% over the integration time.)
- USB power bank 20000mAh 5V 2.4AUnistellar says plain 5 V 2.4 A and warns against fast or adaptive chargers.
- red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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Everything that fits the Odyssey →
How it frames
The M9 is 12′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it fills 36% of the frame’s short side.
About the M9
A small globular near the galactic centre, slightly dimmed by dust. Compact and easy.
NGC 6333 · Globular cluster in Ophiuchus · magnitude 7.7 · 12′ · best in May, Jun, Jul. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
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.
About the Unistellar Odyssey
Unistellar’s compact 85 mm with autofocus and tiny pixels. Sharp, but the fine sampling costs time on faint extended targets. The Odyssey Pro is the same telescope with an eyepiece added, so these figures apply to both.
Fixed 4 s subs in Enhanced Vision; they cannot be changed. No filter option; Unistellar says third-party filters cannot be fitted to the Odyssey.
The Odyssey uses fixed 4 s subs, so the only levers you have are the sky you shoot from, the filter, and total time.
Stack across nights. Every smart scope app can continue a stack or you can combine the saved frames on a computer; the figures here are totals, not single-session limits.
Have an image of the M9 from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M9 with the ZWO Seestar S50: 34 min from Bortle 6
- M9 with the ZWO Seestar S50 Pro: 37 min from Bortle 6
- M9 with the ZWO Seestar S30: 35 min from Bortle 6
- M9 with the ZWO Seestar S30 Pro: 39 min from Bortle 6
- M9 with the DwarfLab DWARF 3: 49 min from Bortle 6
- M9 with the DwarfLab DWARF mini: 34 min from Bortle 6
- M9 with the DwarfLab Draco: 28 min from Bortle 6
- M9 with the DwarfLab DWARF II: 1 h 54 min from Bortle 6
- M9 with the Vaonis Vespera II: 34 min from Bortle 6
- M9 with the Vaonis Vespera Pro: 1 h 15 min from Bortle 6
- M9 with the Vaonis Vespera 3: 32 min from Bortle 6
- M9 with the Vaonis Vespera Pro 2: 1 h 12 min from Bortle 6
- M9 with the Unistellar eQuinox 2: 30 min from Bortle 6
- M9 with the Celestron Origin: 9 min from Bortle 6
- M9 with the Celestron Origin Mark II: 12 min from Bortle 6