How long to image the Heart Nebula with the ZWO Seestar S30 Pro
From a Bortle 6 suburban sky, the ZWO Seestar S30 Pro needs about 3 h 25 min (1,232 subs of 10 s with the built-in dual-band (LP filter) filter) for a solid image of the Heart Nebula. A quick look takes 51 min; a showpiece 14 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 24 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 45% 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 | 34 min207 subs | 2 h 18 min827 subs | 9 h 11 min3,307 subs |
| Bortle 2Typical dark site | 35 min210 subs | 2 h 20 min839 subs | 9 h 19 min3,356 subs |
| Bortle 3Rural | 36 min216 subs | 2 h 24 min863 subs | 9 h 35 min3,450 subs |
| Bortle 4Rural / suburban transition | 38 min230 subs | 2 h 33 min920 subs | 10 h3,678 subs |
| Bortle 5Suburban | 42 min253 subs | 2 h 48 min1,010 subs | 11 h4,039 subs |
| Bortle 6Bright suburban | 51 min308 subs | 3 h 25 min1,232 subs | 14 h4,925 subs |
| Bortle 7Suburban / urban transition | 1 h 09 min414 subs | 4 h 36 min1,654 subs | 18 h6,614 subs |
| Bortle 8City | 1 h 36 min578 subs | 6 h 25 min2,309 subs | 26 h9,235 subs |
| Bortle 9Inner city | 2 h 34 min927 subs | 10 h3,707 subs | 41 h14,825 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 4 h 27 min of run time. The Seestar S30 Pro’s battery is rated at about 5 h, less near freezing, so the session 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-C power bank 10000mAh 5V 3A5 V 3 A input and it runs while charging.
- Seestar S30 Pro dew shieldActive anti-dew is built in; a shield adds margin. The S30 Pro front differs from the S30, so check the listing.
- 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 Seestar S30 Pro →
How it frames
The Heart Nebula is 60′ across. The Seestar S30 Pro frames 3.99° × 2.24° at 3.74″ per pixel, so it fills 45% 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 24 min863 subs | 2 h 48 min1,010 subs | 4 h 36 min1,654 subs |
| 20 s | 1 h 40 min301 subs | 2 h 05 min375 subs | 3 h 52 min696 subs |
| 30 s | 1 h 26 min172 subs | 1 h 50 min221 subs | 3 h 37 min435 subs |
| 60 s | 1 h 11 min72 subs | 1 h 36 min96 subs | 3 h 23 min203 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| UV/IR-cut (no light-pollution filter) | 2 h722 subs | 3 h 20 min1,203 subs | 9 h 11 min3,306 subs |
| dual-band (LP filter) | 2 h 24 min863 subs | 2 h 48 min1,010 subs | 4 h 36 min1,654 subs |
About the Heart Nebula
A degree-wide hydrogen cloud shaped like a heart, with the bright Melotte 15 cluster and pillars at its centre. Dual-band, and a wide field or mosaic.
IC 1805, Sh2-190 · Emission nebula in Cassiopeia · magnitude 6.5 · 60′ · best in Oct, Nov, Dec. 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 Pro
The S30 optics upgraded to a quadruplet in front of an 8 MP IMX585. Same speed per pixel as the S30, four times the pixels, so you can crop hard.
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 on the telephoto camera.
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 Heart Nebula from a Seestar S30 Pro? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Heart Nebula with the ZWO Seestar S50: 2 h 49 min from Bortle 6
- Heart Nebula with the ZWO Seestar S50 Pro: 3 h 10 min from Bortle 6
- Heart Nebula with the ZWO Seestar S30: 3 h 19 min from Bortle 6
- Heart Nebula with the DwarfLab DWARF 3: 3 h 27 min from Bortle 6
- Heart Nebula with the DwarfLab DWARF mini: 2 h 47 min from Bortle 6
- Heart Nebula with the DwarfLab Draco: 2 h 14 min from Bortle 6
- Heart Nebula with the DwarfLab DWARF II: 16 h from Bortle 6
- Heart Nebula with the Vaonis Vespera II: 4 h 37 min from Bortle 6
- Heart Nebula with the Vaonis Vespera Pro: 10 h from Bortle 6
- Heart Nebula with the Vaonis Vespera 3: 4 h 24 min from Bortle 6
- Heart Nebula with the Vaonis Vespera Pro 2: 9 h 52 min from Bortle 6
- Heart Nebula with the Unistellar eQuinox 2: 4 h 14 min from Bortle 6
- Heart Nebula with the Unistellar Odyssey: 20 h from Bortle 6
- Heart Nebula with the Celestron Origin: 1 h 13 min from Bortle 6
- Heart Nebula with the Celestron Origin Mark II: 1 h 40 min from Bortle 6
All telescopes for the Heart Nebula · All targets for the Seestar S30 Pro