How long to image the Tulip Nebula with the ZWO Seestar S30
From a Bortle 6 suburban sky, the ZWO Seestar S30 needs about 2 h 47 min (1,003 subs of 10 s with the built-in dual-band (LP filter) filter) for a solid image of the Tulip Nebula. A quick look takes 42 min; a showpiece 11 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 02 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 22% 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 | 29 min177 subs | 1 h 58 min707 subs | 7 h 51 min2,826 subs |
| Bortle 2Typical dark site | 30 min179 subs | 1 h 59 min716 subs | 7 h 57 min2,862 subs |
| Bortle 3Rural | 31 min184 subs | 2 h 02 min733 subs | 8 h 08 min2,931 subs |
| Bortle 4Rural / suburban transition | 32 min194 subs | 2 h 09 min775 subs | 8 h 36 min3,097 subs |
| Bortle 5Suburban | 35 min211 subs | 2 h 20 min841 subs | 9 h 20 min3,361 subs |
| Bortle 6Bright suburban | 42 min251 subs | 2 h 47 min1,003 subs | 11 h4,009 subs |
| Bortle 7Suburban / urban transition | 55 min328 subs | 3 h 38 min1,311 subs | 15 h5,243 subs |
| Bortle 8City | 1 h 15 min448 subs | 4 h 58 min1,790 subs | 20 h7,159 subs |
| Bortle 9Inner city | 1 h 57 min703 subs | 7 h 49 min2,812 subs | 31 h11,246 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 37 min of run time. The Seestar S30’s battery (rated about 6 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 10000mAh 5V 3A6,000 mAh inside; a 10,000 mAh 5 V 3 A bank roughly doubles a session.
- Seestar S30 dew shieldHeater is built in; a cheap shield reduces dew and stray light.
- 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 Seestar S30 →
How it frames
The Tulip Nebula is 16′ × 9′ across. The Seestar S30 frames 2.13° × 1.20° at 3.99″ per pixel, so it fills 22% of the frame’s short side.
Longer subs
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, which needs the TH10 head. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 2 h 02 min733 subs | 2 h 20 min841 subs | 3 h 38 min1,311 subs |
| 20 s | 1 h 22 min246 subs | 1 h 40 min300 subs | 2 h 58 min535 subs |
| 30 s | 1 h 08 min137 subs | 1 h 26 min173 subs | 2 h 45 min330 subs |
| 60 s | 55 min55 subs | 1 h 13 min73 subs | 2 h 31 min152 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| UV/IR-cut (no light-pollution filter) | 1 h 37 min580 subs | 2 h 35 min932 subs | 6 h 51 min2,469 subs |
| dual-band (LP filter) | 2 h 02 min733 subs | 2 h 20 min841 subs | 3 h 38 min1,311 subs |
About the Tulip Nebula
A compact hydrogen bloom in Cygnus near the black hole Cygnus X-1. Small and moderately faint; dual-band.
Sh2-101 · Emission nebula in Cygnus · magnitude 9.0 · 16′ × 9′ · best in Jul, Aug, Sep. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Emission nebulae glow in a few narrow lines, mostly hydrogen-alpha (deep red) and doubly ionised oxygen (teal). A dual-band filter passes those lines and blocks most skyglow, which is why it cuts the time needed from a suburban sky so dramatically. Use it. From a genuinely dark site the gain is smaller because there is less skyglow to block, and read noise becomes the limit, which is where longer subs (EQ mode, or Expert Mode on a Vespera) earn their keep.
Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.
About the ZWO Seestar S30
Wider and lighter than the S50 with the same 2.9 µm pixels, so its per-pixel speed on extended targets is close despite the smaller aperture. Ideal for big nebulae.
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, which needs the TH10 head. Built-in UV/IR-cut, dual-band (OIII 30 nm / Hα 20 nm) and dark filters.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 10 s and 60 s subs is small; from a rural site it can halve the total time, especially with a dual-band filter in place.
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 Tulip Nebula from a Seestar S30? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Tulip Nebula with the ZWO Seestar S50: 2 h 22 min from Bortle 6
- Tulip Nebula with the ZWO Seestar S50 Pro: 2 h 40 min from Bortle 6
- Tulip Nebula with the ZWO Seestar S30 Pro: 2 h 53 min from Bortle 6
- Tulip Nebula with the DwarfLab DWARF 3: 2 h 55 min from Bortle 6
- Tulip Nebula with the DwarfLab DWARF mini: 2 h 20 min from Bortle 6
- Tulip Nebula with the DwarfLab Draco: 1 h 52 min from Bortle 6
- Tulip Nebula with the DwarfLab DWARF II: 13 h from Bortle 6
- Tulip Nebula with the Vaonis Vespera II: 3 h 51 min from Bortle 6
- Tulip Nebula with the Vaonis Vespera Pro: 8 h 39 min from Bortle 6
- Tulip Nebula with the Vaonis Vespera 3: 3 h 41 min from Bortle 6
- Tulip Nebula with the Vaonis Vespera Pro 2: 8 h 15 min from Bortle 6
- Tulip Nebula with the Unistellar eQuinox 2: 3 h 32 min from Bortle 6
- Tulip Nebula with the Unistellar Odyssey: 16 h from Bortle 6
- Tulip Nebula with the Celestron Origin: 1 h 01 min from Bortle 6
- Tulip Nebula with the Celestron Origin Mark II: 1 h 24 min from Bortle 6
All telescopes for the Tulip Nebula · All targets for the Seestar S30