How long to image the Crab Nebula with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 34 min (503 subs of 4 s) for a solid image of the Crab Nebula. A quick look takes 8 min; a showpiece 2 h 14 min. Under a Bortle 3 rural sky the solid figure drops to 21 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 18% 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 | 5 min73 subs | 19 min289 subs | 1 h 17 min1,156 subs |
| Bortle 2Typical dark site | 5 min74 subs | 20 min296 subs | 1 h 19 min1,182 subs |
| Bortle 3Rural | 5 min77 subs | 21 min308 subs | 1 h 22 min1,232 subs |
| Bortle 4Rural / suburban transition | 6 min85 subs | 23 min338 subs | 1 h 30 min1,352 subs |
| Bortle 5Suburban | 6 min97 subs | 26 min386 subs | 1 h 43 min1,543 subs |
| Bortle 6Bright suburban | 8 min126 subs | 34 min503 subs | 2 h 14 min2,011 subs |
| Bortle 7Suburban / urban transition | 12 min182 subs | 48 min726 subs | 3 h 13 min2,902 subs |
| Bortle 8City | 18 min268 subs | 1 h 11 min1,072 subs | 4 h 46 min4,287 subs |
| Bortle 9Inner city | 30 min453 subs | 2 h 01 min1,810 subs | 8 h 03 min7,240 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 44 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, and 30% off the battery for a December night.)
- 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.
- hand warmers long lastingAir-activated packs give hours of heat for the person; winter nights are long and you spend most of them standing still.
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Everything that fits the eQuinox 2 →
How it frames
The Crab Nebula is 6′ × 4′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 18% of the frame’s short side.
Filters
The Crab 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 Crab Nebula
The remains of the supernova of 1054, a tangle of filaments around a pulsar. Small but bright enough for a good result in an evening.
M1, NGC 1952 · Supernova remnant in Taurus · magnitude 8.4 · 6′ × 4′ · best in Nov, Dec, Jan. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Supernova remnants are emission-line objects, strong in both hydrogen-alpha and OIII, and their filaments are thin, so pixel scale matters as much as aperture. A dual-band filter is essential from any lit sky and still helps under a dark one. These are long-integration targets; plan on several sessions and stack across nights.
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 Crab 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
- Crab Nebula with the ZWO Seestar S50: 28 min from Bortle 6
- Crab Nebula with the ZWO Seestar S50 Pro: 31 min from Bortle 6
- Crab Nebula with the ZWO Seestar S30: 31 min from Bortle 6
- Crab Nebula with the ZWO Seestar S30 Pro: 33 min from Bortle 6
- Crab Nebula with the DwarfLab DWARF 3: 37 min from Bortle 6
- Crab Nebula with the DwarfLab DWARF mini: 28 min from Bortle 6
- Crab Nebula with the DwarfLab Draco: 22 min from Bortle 6
- Crab Nebula with the DwarfLab DWARF II: 2 h 08 min from Bortle 6
- Crab Nebula with the Vaonis Vespera II: 38 min from Bortle 6
- Crab Nebula with the Vaonis Vespera Pro: 1 h 25 min from Bortle 6
- Crab Nebula with the Vaonis Vespera 3: 37 min from Bortle 6
- Crab Nebula with the Vaonis Vespera Pro 2: 1 h 21 min from Bortle 6
- Crab Nebula with the Unistellar Odyssey: 2 h 32 min from Bortle 6
- Crab Nebula with the Celestron Origin: 10 min from Bortle 6
- Crab Nebula with the Celestron Origin Mark II: 14 min from Bortle 6
All telescopes for the Crab Nebula · All targets for the eQuinox 2