How long to image the Pleiades with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 11 h (10,297 subs of 4 s) for a solid image of the Pleiades. A quick look takes 2 h 52 min; a showpiece 46 h. Under a Bortle 3 rural sky the solid figure drops to 7 h 36 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it is 3.3× wider than the frame.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 1 h 48 min1,627 subs | 7 h 14 min6,507 subs | 29 h26,025 subs |
| Bortle 2Typical dark site | 1 h 50 min1,656 subs | 7 h 21 min6,623 subs | 29 h26,490 subs |
| Bortle 3Rural | 1 h 54 min1,711 subs | 7 h 36 min6,843 subs | 30 h27,371 subs |
| Bortle 4Rural / suburban transition | 2 h 03 min1,845 subs | 8 h 12 min7,377 subs | 33 h29,505 subs |
| Bortle 5Suburban | 2 h 17 min2,056 subs | 9 h 08 min8,222 subs | 37 h32,887 subs |
| Bortle 6Bright suburban | 2 h 52 min2,575 subs | 11 h10,297 subs | 46 h41,186 subs |
| Bortle 7Suburban / urban transition | 3 h 57 min3,563 subs | 16 h14,250 subs | 63 h56,998 subs |
| Bortle 8City | 5 h 40 min5,097 subs | 23 h20,387 subs | 91 h81,548 subs |
| Bortle 9Inner city | 9 h 18 min8,370 subs | 37 h33,477 subs | 150+ h133,907 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 15 h of run time. That is more than one night: over 3 nights, about 4 h 57 min each. The Odyssey’s battery is rated at about 5 h, less near freezing, so each night needs an external power bank. (Bortle 6, solid image; we allow 30% over the integration time, and 30% off the battery for a November night.)
- USB power bank 20000mAh 5V 2.4AUnistellar says plain 5 V 2.4 A and warns against fast or adaptive chargers.
- 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 Odyssey →
How it frames
The Pleiades is 110′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it is 3.3× wider than the frame. A mosaic, or choosing the part you want and letting the rest go, is how it gets shot on this scope.
About the Pleiades
The stars take seconds. The blue reflection nebulosity around them is faint and needs hours from any sky, and no filter helps because it is starlight, not emission.
M45, Seven Sisters · Reflection nebula in Taurus · magnitude 1.6 · 110′ · best in Oct, Nov, Dec. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Reflection nebulae are starlight scattered by dust, so they are broadband and blue. A dual-band filter removes almost all of it; do not use one. These are among the faintest structures a smart scope can attempt and the figures run long. A dark sky matters more here than for any other type, and the Moon must be down.
About the Unistellar Odyssey
Unistellar’s compact 85 mm with autofocus and tiny pixels. Sharp, but the fine sampling costs time on faint extended targets. The Odyssey Pro is the same telescope with an eyepiece added, so these figures apply to both.
Fixed 4 s subs in Enhanced Vision; they cannot be changed. No filter option; Unistellar says third-party filters cannot be fitted to the Odyssey.
The Odyssey 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 Pleiades from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Pleiades with the ZWO Seestar S50: 2 h 42 min from Bortle 6
- Pleiades with the ZWO Seestar S50 Pro: 2 h 57 min from Bortle 6
- Pleiades with the ZWO Seestar S30: 2 h 50 min from Bortle 6
- Pleiades with the ZWO Seestar S30 Pro: 3 h 08 min from Bortle 6
- Pleiades with the DwarfLab DWARF 3: 3 h 55 min from Bortle 6
- Pleiades with the DwarfLab DWARF mini: 2 h 41 min from Bortle 6
- Pleiades with the DwarfLab Draco: 2 h 13 min from Bortle 6
- Pleiades with the DwarfLab DWARF II: 9 h 16 min from Bortle 6
- Pleiades with the Vaonis Vespera II: 2 h 42 min from Bortle 6
- Pleiades with the Vaonis Vespera Pro: 6 h 03 min from Bortle 6
- Pleiades with the Vaonis Vespera 3: 2 h 35 min from Bortle 6
- Pleiades with the Vaonis Vespera Pro 2: 5 h 46 min from Bortle 6
- Pleiades with the Unistellar eQuinox 2: 2 h 28 min from Bortle 6
- Pleiades with the Celestron Origin: 43 min from Bortle 6
- Pleiades with the Celestron Origin Mark II: 59 min from Bortle 6
All telescopes for the Pleiades · All targets for the Odyssey