How long to image the Centaurus A with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 37 min (551 subs of 4 s) for a solid image of the Centaurus A. A quick look takes 9 min; a showpiece 2 h 27 min. Under a Bortle 3 rural sky the solid figure drops to 22 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 76% 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 min76 subs | 20 min304 subs | 1 h 21 min1,216 subs |
| Bortle 2Typical dark site | 5 min78 subs | 21 min312 subs | 1 h 23 min1,246 subs |
| Bortle 3Rural | 5 min82 subs | 22 min326 subs | 1 h 27 min1,303 subs |
| Bortle 4Rural / suburban transition | 6 min91 subs | 24 min361 subs | 1 h 36 min1,443 subs |
| Bortle 5Suburban | 7 min104 subs | 28 min416 subs | 1 h 51 min1,663 subs |
| Bortle 6Bright suburban | 9 min138 subs | 37 min551 subs | 2 h 27 min2,203 subs |
| Bortle 7Suburban / urban transition | 13 min203 subs | 54 min809 subs | 3 h 36 min3,234 subs |
| Bortle 8City | 20 min303 subs | 1 h 21 min1,209 subs | 5 h 22 min4,833 subs |
| Bortle 9Inner city | 34 min516 subs | 2 h 17 min2,061 subs | 9 h 10 min8,244 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 48 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 Centaurus A is 26′ × 20′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 76% of the frame’s short side.
About the Centaurus A
A giant elliptical with a thick dust band across it, the brightest radio galaxy in the sky. A southern-hemisphere showpiece.
NGC 5128, Caldwell 77 · Galaxy in Centaurus · magnitude 6.8 · 26′ × 20′ · best in Mar, Apr, May. Low or below the horizon from northern Europe; best from the southern US southwards.
Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.
Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.
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 Centaurus A from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Centaurus A with the ZWO Seestar S50: 41 min from Bortle 6
- Centaurus A with the ZWO Seestar S50 Pro: 45 min from Bortle 6
- Centaurus A with the ZWO Seestar S30: 43 min from Bortle 6
- Centaurus A with the ZWO Seestar S30 Pro: 48 min from Bortle 6
- Centaurus A with the DwarfLab DWARF 3: 1 h from Bortle 6
- Centaurus A with the DwarfLab DWARF mini: 41 min from Bortle 6
- Centaurus A with the DwarfLab Draco: 34 min from Bortle 6
- Centaurus A with the DwarfLab DWARF II: 2 h 19 min from Bortle 6
- Centaurus A with the Vaonis Vespera II: 41 min from Bortle 6
- Centaurus A with the Vaonis Vespera Pro: 1 h 32 min from Bortle 6
- Centaurus A with the Vaonis Vespera 3: 39 min from Bortle 6
- Centaurus A with the Vaonis Vespera Pro 2: 1 h 27 min from Bortle 6
- Centaurus A with the Unistellar Odyssey: 2 h 49 min from Bortle 6
- Centaurus A with the Celestron Origin: 11 min from Bortle 6
- Centaurus A with the Celestron Origin Mark II: 15 min from Bortle 6
All telescopes for the Centaurus A · All targets for the eQuinox 2