Elephant's Trunk Nebula
IC 1396 · Emission nebula in Cepheus
- Magnitude
- 3.5
- Size
- 170′ × 140′
- Effective surface brightness
- 22.7 mag/arcsec²
- Best months
- Jul, Aug, Sep
- Declination
- +58°
- Filter
- Dual-band recommended
A vast, faint hydrogen cloud in Cepheus with the dark trunk winding through it. Huge, so wide scopes frame the whole thing; dual-band is essential from any lit sky.
Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
How long with each smart telescope
| Telescope | Bortle 3 (rural) | Bortle 5 (suburban) | Bortle 7 (urban edge) |
|---|---|---|---|
| ZWO Seestar S5010 s subs, dual-band | 2 h 47 min1,005 subs | 3 h 05 min1,113 subs | 4 h 24 min1,583 subs |
| ZWO Seestar S50 Pro10 s subs, dual-band | 1 h 51 min668 subs | 2 h 11 min785 subs | 3 h 36 min1,294 subs |
| ZWO Seestar S3010 s subs, dual-band | 1 h 37 min585 subs | 1 h 55 min693 subs | 3 h 14 min1,163 subs |
| ZWO Seestar S30 Pro10 s subs, dual-band | 2 h 01 min729 subs | 2 h 22 min851 subs | 3 h 51 min1,387 subs |
| DwarfLab Dwarf 315 s subs, dual-band | 2 h 43 min651 subs | 3 h 10 min761 subs | 5 h 11 min1,246 subs |
| DwarfLab Dwarf Mini15 s subs, dual-band | 1 h 19 min316 subs | 1 h 37 min387 subs | 2 h 55 min701 subs |
| DwarfLab Dwarf II15 s subs | 6 h 29 min1,557 subs | 9 h 12 min2,208 subs | 21 h5,054 subs |
| Vaonis Vespera II10 s subs | 1 h 25 min508 subs | 2 h 23 min859 subs | 6 h 39 min2,396 subs |
| Vaonis Vespera Pro10 s subs | 4 h 14 min1,525 subs | 6 h 17 min2,264 subs | 15 h5,496 subs |
| Unistellar eQuinox 24 s subs | 2 h 01 min1,811 subs | 2 h 37 min2,359 subs | 5 h 17 min4,753 subs |
| Unistellar Odyssey4 s subs | 11 h9,803 subs | 13 h11,796 subs | 23 h20,509 subs |
| Celestron Origin10 s subs | 19 min117 subs | 36 min217 subs | 1 h 49 min653 subs |
Imaging the emission nebula
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) earn their keep.
Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.
Per-telescope pages
- How long to image the Elephant's Trunk Nebula with the ZWO Seestar S50
- How long to image the Elephant's Trunk Nebula with the ZWO Seestar S50 Pro
- How long to image the Elephant's Trunk Nebula with the ZWO Seestar S30
- How long to image the Elephant's Trunk Nebula with the ZWO Seestar S30 Pro
- How long to image the Elephant's Trunk Nebula with the DwarfLab Dwarf 3
- How long to image the Elephant's Trunk Nebula with the DwarfLab Dwarf Mini
- How long to image the Elephant's Trunk Nebula with the DwarfLab Dwarf II
- How long to image the Elephant's Trunk Nebula with the Vaonis Vespera II
- How long to image the Elephant's Trunk Nebula with the Vaonis Vespera Pro
- How long to image the Elephant's Trunk Nebula with the Unistellar eQuinox 2
- How long to image the Elephant's Trunk Nebula with the Unistellar Odyssey
- How long to image the Elephant's Trunk Nebula with the Celestron Origin