How long to image the Flaming Star Nebula with the DwarfLab DWARF 3
From a Bortle 6 suburban sky, the DwarfLab DWARF 3 needs about 2 h 05 min (500 subs of 15 s with the built-in dual-band filter) for a solid image of the Flaming Star Nebula. A quick look takes 31 min; a showpiece 8 h 20 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 17 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 30% 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 | 18 min73 subs | 1 h 12 min290 subs | 4 h 49 min1,157 subs |
| Bortle 2Typical dark site | 18 min74 subs | 1 h 14 min296 subs | 4 h 55 min1,182 subs |
| Bortle 3Rural | 19 min77 subs | 1 h 17 min308 subs | 5 h 08 min1,231 subs |
| Bortle 4Rural / suburban transition | 21 min85 subs | 1 h 24 min338 subs | 5 h 37 min1,350 subs |
| Bortle 5Suburban | 24 min97 subs | 1 h 36 min385 subs | 6 h 24 min1,538 subs |
| Bortle 6Bright suburban | 31 min125 subs | 2 h 05 min500 subs | 8 h 20 min2,000 subs |
| Bortle 7Suburban / urban transition | 45 min180 subs | 3 h720 subs | 12 h2,879 subs |
| Bortle 8City | 1 h 06 min266 subs | 4 h 25 min1,061 subs | 18 h4,244 subs |
| Bortle 9Inner city | 1 h 52 min448 subs | 7 h 27 min1,789 subs | 30 h7,155 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 42 min of run time. The DWARF 3’s battery (rated about 5 h 30 min) 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 PD power bank 20000mAh 18W18 W PD input and it runs while charging; needs a C-to-C cable for PD.
- 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 DWARF 3 →
How it frames
The Flaming Star Nebula is 30′ × 19′ across. The DWARF 3 frames 2.93° × 1.65° at 2.75″ per pixel, so it fills 30% of the frame’s short side.
Longer subs
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 60 s is the ceiling on the tele camera. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 15 s | 1 h 17 min308 subs | 1 h 36 min385 subs | 3 h720 subs |
| 30 s | 1 h 06 min132 subs | 1 h 25 min171 subs | 2 h 49 min338 subs |
| 60 s | 1 h61 subs | 1 h 19 min80 subs | 2 h 43 min164 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| Astro (no light-pollution filter) | 1 h 18 min312 subs | 2 h 20 min562 subs | 6 h 54 min1,657 subs |
| dual-band | 1 h 17 min308 subs | 1 h 36 min385 subs | 3 h720 subs |
About the Flaming Star Nebula
Emission and reflection lit by the runaway star AE Aurigae. Dual-band for the red; a broadband stack adds the blue.
IC 405, Caldwell 31 · Emission nebula in Auriga · magnitude 6.0 · 30′ × 19′ · best in Nov, Dec, Jan. 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 DwarfLab DWARF 3
Small pixels on a 35 mm f/4.3 lens give a sharper image than its aperture suggests, and EQ mode with 60 s subs makes it the read-noise winner in dark skies.
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 60 s is the ceiling on the tele camera. Three built-in filters: VIS, Astro (430 to 690 nm) and dual-band Hα 656 nm / OIII 501 nm.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 15 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 Flaming Star Nebula from a DWARF 3? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Flaming Star Nebula with the ZWO Seestar S50: 1 h 41 min from Bortle 6
- Flaming Star Nebula with the ZWO Seestar S50 Pro: 1 h 53 min from Bortle 6
- Flaming Star Nebula with the ZWO Seestar S30: 1 h 58 min from Bortle 6
- Flaming Star Nebula with the ZWO Seestar S30 Pro: 2 h 02 min from Bortle 6
- Flaming Star Nebula with the DwarfLab DWARF mini: 1 h 40 min from Bortle 6
- Flaming Star Nebula with the DwarfLab Draco: 1 h 20 min from Bortle 6
- Flaming Star Nebula with the DwarfLab DWARF II: 9 h 16 min from Bortle 6
- Flaming Star Nebula with the Vaonis Vespera II: 2 h 42 min from Bortle 6
- Flaming Star Nebula with the Vaonis Vespera Pro: 6 h 03 min from Bortle 6
- Flaming Star Nebula with the Vaonis Vespera 3: 2 h 35 min from Bortle 6
- Flaming Star Nebula with the Vaonis Vespera Pro 2: 5 h 46 min from Bortle 6
- Flaming Star Nebula with the Unistellar eQuinox 2: 2 h 28 min from Bortle 6
- Flaming Star Nebula with the Unistellar Odyssey: 11 h from Bortle 6
- Flaming Star Nebula with the Celestron Origin: 43 min from Bortle 6
- Flaming Star Nebula with the Celestron Origin Mark II: 59 min from Bortle 6
All telescopes for the Flaming Star Nebula · All targets for the DWARF 3