How long to image the M9 with the Celestron Origin Mark II
From a Bortle 6 suburban sky, the Celestron Origin Mark II needs about 12 min (75 subs of 10 s) for a solid image of the M9. A quick look takes 3 min; a showpiece 49 min. Under a Bortle 3 rural sky the solid figure drops to 5 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 27% 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 | 2 min10 subs | 5 min30 subs | 15 min91 subs |
| Bortle 2Typical dark site | 2 min10 subs | 5 min30 subs | 16 min97 subs |
| Bortle 3Rural | 2 min10 subs | 5 min30 subs | 18 min109 subs |
| Bortle 4Rural / suburban transition | 2 min10 subs | 6 min35 subs | 23 min138 subs |
| Bortle 5Suburban | 2 min12 subs | 8 min46 subs | 31 min184 subs |
| Bortle 6Bright suburban | 3 min19 subs | 12 min75 subs | 49 min297 subs |
| Bortle 7Suburban / urban transition | 5 min33 subs | 21 min129 subs | 1 h 25 min513 subs |
| Bortle 8City | 9 min53 subs | 35 min212 subs | 2 h 21 min847 subs |
| Bortle 9Inner city | 16 min98 subs | 1 h 05 min390 subs | 4 h 20 min1,560 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 16 min of run time. The Origin Mark II’s battery (rated about 6 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.)
- portable power station 300W AC outletRuns the supplied 12 V adapter off-grid; dew shield and heater are built in.
- 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 Origin Mark II →
How it frames
The M9 is 12′ across. The Origin Mark II frames 1.32° × 0.75° at 1.23″ per pixel, so it fills 27% of the frame’s short side.
Longer subs
10 s auto subs (15 s with the Nebula Filter); manual 1 to 30 s on the alt-az mount, longer only with the EQ wedge, and 60 s and up needs the StarSense Autoguider too. Celestron warns the f/2.2 optics saturate quickly without the filter. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 5 min30 subs | 8 min46 subs | 21 min129 subs |
| 15 s | 8 min30 subs | 8 min31 subs | 21 min86 subs |
| 30 s | 15 min30 subs | 15 min30 subs | 21 min43 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 Celestron Origin Mark II
The Origin Mark II (late 2025): the same 6-inch f/2.2 RASA with an 8 MP IMX678 in place of the original 6 MP IMX178. Smaller pixels for finer detail, a quieter sensor, and still the fastest system here by a wide margin.
10 s auto subs (15 s with the Nebula Filter); manual 1 to 30 s on the alt-az mount, longer only with the EQ wedge, and 60 s and up needs the StarSense Autoguider too. Celestron warns the f/2.2 optics saturate quickly without the filter. Filter drawer takes 1.25-inch or 2-inch filters, including dual-band; Celestron sells an optional Nebula Filter.
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 Origin Mark II? 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 Unistellar Odyssey: 2 h 17 min from Bortle 6
- M9 with the Celestron Origin: 9 min from Bortle 6
All telescopes for the M9 · All targets for the Origin Mark II