How long to image the M9 with the Vaonis Vespera Pro
From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 1 h 15 min (452 subs of 10 s) for a solid image of the M9. A quick look takes 19 min; a showpiece 5 h 01 min. Under a Bortle 3 rural sky the solid figure drops to 35 min. At Bortle 6 the limit is skyglow, so a darker site or a filter helps more than longer subs. In this scope's field it fills 12% 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 | 8 min47 subs | 31 min186 subs | 2 h 04 min744 subs |
| Bortle 2Typical dark site | 8 min49 subs | 32 min194 subs | 2 h 09 min776 subs |
| Bortle 3Rural | 9 min53 subs | 35 min210 subs | 2 h 20 min838 subs |
| Bortle 4Rural / suburban transition | 10 min62 subs | 41 min247 subs | 2 h 44 min987 subs |
| Bortle 5Suburban | 13 min77 subs | 51 min307 subs | 3 h 24 min1,225 subs |
| Bortle 6Bright suburban | 19 min113 subs | 1 h 15 min452 subs | 5 h 01 min1,806 subs |
| Bortle 7Suburban / urban transition | 30 min183 subs | 2 h 01 min729 subs | 8 h 06 min2,914 subs |
| Bortle 8City | 48 min290 subs | 3 h 13 min1,159 subs | 13 h4,635 subs |
| Bortle 9Inner city | 1 h 27 min520 subs | 5 h 46 min2,077 subs | 23 h8,305 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 38 min of run time. The Vespera Pro’s battery (rated about 11 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-C PD power bank 20000mAh 30WExtends the 11 h battery; 30 W PD per Vaonis.
- 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 Vespera Pro →
How it frames
The M9 is 12′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 12% of the frame’s short side.
Longer subs
10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only, no EQ mode. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 35 min210 subs | 51 min307 subs | 2 h 01 min729 subs |
| 20 s | 30 min90 subs | 46 min138 subs | 1 h 56 min349 subs |
| 30 s | 28 min57 subs | 44 min89 subs | 1 h 55 min230 subs |
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 Vaonis Vespera Pro
The square-sensor Vespera with 2 µm pixels. Higher resolution than the II, and correspondingly slower per pixel: expect around double the time for the same per-pixel SNR. Run-out in 2026 and replaced by the Vespera Pro 2.
10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only, no EQ mode. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 10 s and 30 s subs is small; from a rural site it can halve the total time, especially with a dual-band filter in place.
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 Vespera Pro? 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 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 Unistellar Odyssey: 2 h 17 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