How long to image the Little Dumbbell with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 40 min (598 subs of 4 s) for a solid image of the Little Dumbbell. A quick look takes 10 min; a showpiece 2 h 39 min. Under a Bortle 3 rural sky the solid figure drops to 24 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 8% 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 | 6 min86 subs | 23 min341 subs | 1 h 31 min1,361 subs |
| Bortle 2Typical dark site | 6 min87 subs | 23 min348 subs | 1 h 33 min1,392 subs |
| Bortle 3Rural | 6 min91 subs | 24 min363 subs | 1 h 37 min1,452 subs |
| Bortle 4Rural / suburban transition | 7 min100 subs | 27 min400 subs | 1 h 46 min1,597 subs |
| Bortle 5Suburban | 8 min115 subs | 30 min457 subs | 2 h 02 min1,826 subs |
| Bortle 6Bright suburban | 10 min150 subs | 40 min598 subs | 2 h 39 min2,389 subs |
| Bortle 7Suburban / urban transition | 14 min217 subs | 58 min866 subs | 3 h 51 min3,461 subs |
| Bortle 8City | 21 min321 subs | 1 h 25 min1,282 subs | 5 h 42 min5,125 subs |
| Bortle 9Inner city | 36 min543 subs | 2 h 25 min2,169 subs | 9 h 38 min8,676 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 52 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.
Affiliate links: the retailer pays us a small commission and you pay the same price. These are search links to the named product, not endorsements of a particular listing; check the listing matches your model.
Everything that fits the eQuinox 2 →
How it frames
The Little Dumbbell is 2.7′ × 1.8′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 8% of the frame’s short side.
Filters
The Little Dumbbell 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 Little Dumbbell
A small, bright-per-pixel planetary in Perseus. Dual-band makes the two lobes and the faint wings much easier.
M76, NGC 650 · Planetary nebula in Perseus · magnitude 10.1 · 2.7′ × 1.8′ · best in Sep, Oct, Nov. 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 Little Dumbbell from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Little Dumbbell with the ZWO Seestar S50: 33 min from Bortle 6
- Little Dumbbell with the ZWO Seestar S50 Pro: 36 min from Bortle 6
- Little Dumbbell with the ZWO Seestar S30: 37 min from Bortle 6
- Little Dumbbell with the ZWO Seestar S30 Pro: 39 min from Bortle 6
- Little Dumbbell with the DwarfLab DWARF 3: 43 min from Bortle 6
- Little Dumbbell with the DwarfLab DWARF mini: 32 min from Bortle 6
- Little Dumbbell with the DwarfLab Draco: 26 min from Bortle 6
- Little Dumbbell with the DwarfLab DWARF II: 2 h 32 min from Bortle 6
- Little Dumbbell with the Vaonis Vespera II: 45 min from Bortle 6
- Little Dumbbell with the Vaonis Vespera Pro: 1 h 41 min from Bortle 6
- Little Dumbbell with the Vaonis Vespera 3: 43 min from Bortle 6
- Little Dumbbell with the Vaonis Vespera Pro 2: 1 h 36 min from Bortle 6
- Little Dumbbell with the Unistellar Odyssey: 3 h 01 min from Bortle 6
- Little Dumbbell with the Celestron Origin: 12 min from Bortle 6
- Little Dumbbell with the Celestron Origin Mark II: 17 min from Bortle 6
All telescopes for the Little Dumbbell · All targets for the eQuinox 2