How long to image the Fireworks Galaxy with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 22 h (20,175 subs of 4 s) for a solid image of the Fireworks Galaxy. A quick look takes 5 h 36 min; a showpiece 90 h. Under a Bortle 3 rural sky the solid figure drops to 15 h. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 33% 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 h 32 min3,176 subs | 14 h12,704 subs | 56 h50,814 subs |
| Bortle 2Typical dark site | 3 h 36 min3,234 subs | 14 h12,933 subs | 57 h51,732 subs |
| Bortle 3Rural | 3 h 43 min3,342 subs | 15 h13,367 subs | 59 h53,468 subs |
| Bortle 4Rural / suburban transition | 4 h3,605 subs | 16 h14,419 subs | 64 h57,674 subs |
| Bortle 5Suburban | 4 h 28 min4,022 subs | 18 h16,086 subs | 71 h64,341 subs |
| Bortle 6Bright suburban | 5 h 36 min5,044 subs | 22 h20,175 subs | 90 h80,697 subs |
| Bortle 7Suburban / urban transition | 7 h 46 min6,992 subs | 31 h27,966 subs | 120+ h111,864 subs |
| Bortle 8City | 11 h10,016 subs | 45 h40,064 subs | 180+ h160,254 subs |
| Bortle 9Inner city | 18 h16,466 subs | 73 h65,864 subs | 290+ h263,455 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 29 h of run time. That is more than one night: over 5 nights, about 5 h 50 min each. The Odyssey’s battery is rated at about 5 h, so each night needs an external power bank. (Bortle 6, solid image; we allow 30% over the integration time.)
- 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.
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Everything that fits the Odyssey →
How it frames
The Fireworks Galaxy is 11′ × 10′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it fills 33% of the frame’s short side.
About the Fireworks Galaxy
A face-on spiral famous for its supernovae, dimmed by Milky Way dust. Faint arms; the open cluster NGC 6939 sits nearby.
NGC 6946, Caldwell 12 · Galaxy in Cygnus · magnitude 9.6 · 11′ × 10′ · best in Jul, Aug, Sep. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
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 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 Fireworks Galaxy from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Fireworks Galaxy with the ZWO Seestar S50: 5 h 15 min from Bortle 6
- Fireworks Galaxy with the ZWO Seestar S50 Pro: 5 h 45 min from Bortle 6
- Fireworks Galaxy with the ZWO Seestar S30: 5 h 32 min from Bortle 6
- Fireworks Galaxy with the ZWO Seestar S30 Pro: 6 h 06 min from Bortle 6
- Fireworks Galaxy with the DwarfLab DWARF 3: 7 h 37 min from Bortle 6
- Fireworks Galaxy with the DwarfLab DWARF mini: 5 h 14 min from Bortle 6
- Fireworks Galaxy with the DwarfLab Draco: 4 h 19 min from Bortle 6
- Fireworks Galaxy with the DwarfLab DWARF II: 18 h from Bortle 6
- Fireworks Galaxy with the Vaonis Vespera II: 5 h 15 min from Bortle 6
- Fireworks Galaxy with the Vaonis Vespera Pro: 12 h from Bortle 6
- Fireworks Galaxy with the Vaonis Vespera 3: 5 h 01 min from Bortle 6
- Fireworks Galaxy with the Vaonis Vespera Pro 2: 11 h from Bortle 6
- Fireworks Galaxy with the Unistellar eQuinox 2: 4 h 49 min from Bortle 6
- Fireworks Galaxy with the Celestron Origin: 1 h 23 min from Bortle 6
- Fireworks Galaxy with the Celestron Origin Mark II: 1 h 54 min from Bortle 6
All telescopes for the Fireworks Galaxy · All targets for the Odyssey