How long to image the Dumbbell Nebula with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 24 min (353 subs of 4 s) for a solid image of the Dumbbell Nebula. A quick look takes 6 min; a showpiece 1 h 34 min. Under a Bortle 3 rural sky the solid figure drops to 15 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 23% 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 | 3 min52 subs | 14 min205 subs | 55 min819 subs |
| Bortle 2Typical dark site | 3 min53 subs | 14 min210 subs | 56 min837 subs |
| Bortle 3Rural | 4 min55 subs | 15 min218 subs | 58 min872 subs |
| Bortle 4Rural / suburban transition | 4 min60 subs | 16 min239 subs | 1 h 04 min955 subs |
| Bortle 5Suburban | 5 min68 subs | 18 min272 subs | 1 h 12 min1,088 subs |
| Bortle 6Bright suburban | 6 min89 subs | 24 min353 subs | 1 h 34 min1,412 subs |
| Bortle 7Suburban / urban transition | 8 min127 subs | 34 min508 subs | 2 h 15 min2,030 subs |
| Bortle 8City | 12 min187 subs | 50 min748 subs | 3 h 19 min2,990 subs |
| Bortle 9Inner city | 21 min315 subs | 1 h 24 min1,260 subs | 5 h 36 min5,037 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 31 min of run time. The eQuinox 2’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 power bank 20000mAh 5V 2AUnistellar asks for a 5 V 2 A output; PD is not needed.
- 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 eQuinox 2 →
How it frames
The Dumbbell Nebula is 8′ × 5.7′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 23% of the frame’s short side.
Filters
The Dumbbell Nebula is an emission target, where a dual-band filter would normally cut the time several-fold from a lit sky, but the eQuinox 2 has no dual-band option: No built-in filter. Unistellar sells only a solar filter and says a third-party filter is at your own risk and voids the warranty. The figures above are for the No filter position, and a darker sky is the lever that remains.
About the Dumbbell Nebula
The biggest, brightest planetary nebula for northern observers. Bright enough to look good in twenty minutes, and dual-band brings out the outer shell.
M27, NGC 6853 · Planetary nebula in Vulpecula · magnitude 7.4 · 8′ × 5.7′ · best in Jun, Jul, Aug. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Planetary nebulae are small but intensely bright per pixel in OIII and H-alpha, so they respond very well to a dual-band filter and do not need much time for the main shell. The faint outer halos most of them have are a different proposition and need hours. Keep subs short if the central region saturates.
About the Unistellar eQuinox 2
A 114 mm Newtonian with five times the light grasp of a 50 mm refractor. Fixed 4 s subs put it in read-noise territory under dark skies, but the aperture carries it. The published field is 45.6′ × 34.2′, a crop of the sensor.
Fixed 4 s subs in Enhanced Vision; they cannot be changed. No built-in filter. Unistellar sells only a solar filter and says a third-party filter is at your own risk and voids the warranty.
The eQuinox 2 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 Dumbbell Nebula from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Dumbbell Nebula with the ZWO Seestar S50: 20 min from Bortle 6
- Dumbbell Nebula with the ZWO Seestar S50 Pro: 22 min from Bortle 6
- Dumbbell Nebula with the ZWO Seestar S30: 23 min from Bortle 6
- Dumbbell Nebula with the ZWO Seestar S30 Pro: 24 min from Bortle 6
- Dumbbell Nebula with the DwarfLab DWARF 3: 27 min from Bortle 6
- Dumbbell Nebula with the DwarfLab DWARF mini: 20 min from Bortle 6
- Dumbbell Nebula with the DwarfLab Draco: 16 min from Bortle 6
- Dumbbell Nebula with the DwarfLab DWARF II: 1 h 30 min from Bortle 6
- Dumbbell Nebula with the Vaonis Vespera II: 27 min from Bortle 6
- Dumbbell Nebula with the Vaonis Vespera Pro: 1 h from Bortle 6
- Dumbbell Nebula with the Vaonis Vespera 3: 26 min from Bortle 6
- Dumbbell Nebula with the Vaonis Vespera Pro 2: 57 min from Bortle 6
- Dumbbell Nebula with the Unistellar Odyssey: 1 h 47 min from Bortle 6
- Dumbbell Nebula with the Celestron Origin: 7 min from Bortle 6
- Dumbbell Nebula with the Celestron Origin Mark II: 10 min from Bortle 6
All telescopes for the Dumbbell Nebula · All targets for the eQuinox 2