Horsehead Nebula
IC 434, Barnard 33 · Emission nebula in Orion
- Magnitude
- 7.3
- Size
- 60′ × 10′
- Effective surface brightness
- 22.6 mag/arcsec²
- Best months
- Nov, Dec, Jan
- Declination
- -2°
- Filter
- Dual-band recommended
The horse's head is a dark cloud in front of the glowing IC 434 ribbon. You image the ribbon; the head is what is missing. Dual-band, and expect a few hours from suburbia.
Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
How long with each smart telescope
| Telescope | In frame | Bortle 3 (rural) | Bortle 5 (suburban) | Bortle 7 (urban edge) |
|---|---|---|---|---|
| ZWO Seestar S5010 s subs, dual-band | 1.4× frame | 1 h 23 min496 subs | 1 h 37 min585 subs | 2 h 43 min976 subs |
| ZWO Seestar S50 Pro10 s subs, dual-band | 72% | 1 h 34 min566 subs | 1 h 50 min662 subs | 3 h 01 min1,086 subs |
| ZWO Seestar S3010 s subs, dual-band | 84% | 1 h 43 min619 subs | 1 h 58 min708 subs | 3 h 03 min1,099 subs |
| ZWO Seestar S30 Pro10 s subs, dual-band | 45% | 1 h 43 min616 subs | 2 h718 subs | 3 h 14 min1,163 subs |
| DwarfLab DWARF 315 s subs, dual-band | 61% | 1 h 30 min361 subs | 1 h 53 min453 subs | 3 h 34 min856 subs |
| DwarfLab DWARF mini15 s subs, dual-band | 84% | 1 h 21 min323 subs | 1 h 36 min383 subs | 2 h 41 min644 subs |
| DwarfLab Draco30 s subs, dual-band | 80% | 1 h 04 min128 subs | 1 h 16 min153 subs | 2 h 10 min261 subs |
| DwarfLab DWARF II15 s subs | 56% | 5 h 26 min1,306 subs | 7 h 42 min1,848 subs | 18 h4,215 subs |
| Vaonis Vespera II10 s subs | 70% | 1 h 11 min429 subs | 2 h721 subs | 5 h 33 min1,999 subs |
| Vaonis Vespera Pro10 s subs | 62% | 2 h 57 min1,064 subs | 4 h 40 min1,679 subs | 12 h4,366 subs |
| Vaonis Vespera 310 s subs | 68% | 1 h 07 min405 subs | 1 h 54 min686 subs | 5 h 19 min1,914 subs |
| Vaonis Vespera Pro 210 s subs | 60% | 2 h 47 min1,002 subs | 4 h 25 min1,593 subs | 12 h4,174 subs |
| Unistellar eQuinox 24 s subs | 1.8× frame | 1 h 41 min1,516 subs | 2 h 11 min1,971 subs | 4 h 24 min3,963 subs |
| Unistellar Odyssey4 s subs | 1.8× frame | 9 h 06 min8,189 subs | 11 h9,847 subs | 19 h17,094 subs |
| Celestron Origin10 s subs | 1.2× frame | 16 min99 subs | 30 min182 subs | 1 h 31 min545 subs |
| Celestron Origin Mark II10 s subs | 1.3× frame | 20 min121 subs | 40 min240 subs | 2 h 07 min763 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, 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.
Per-telescope pages
- How long to image the Horsehead Nebula with the ZWO Seestar S50
- How long to image the Horsehead Nebula with the ZWO Seestar S50 Pro
- How long to image the Horsehead Nebula with the ZWO Seestar S30
- How long to image the Horsehead Nebula with the ZWO Seestar S30 Pro
- How long to image the Horsehead Nebula with the DwarfLab DWARF 3
- How long to image the Horsehead Nebula with the DwarfLab DWARF mini
- How long to image the Horsehead Nebula with the DwarfLab Draco
- How long to image the Horsehead Nebula with the DwarfLab DWARF II
- How long to image the Horsehead Nebula with the Vaonis Vespera II
- How long to image the Horsehead Nebula with the Vaonis Vespera Pro
- How long to image the Horsehead Nebula with the Vaonis Vespera 3
- How long to image the Horsehead Nebula with the Vaonis Vespera Pro 2
- How long to image the Horsehead Nebula with the Unistellar eQuinox 2
- How long to image the Horsehead Nebula with the Unistellar Odyssey
- How long to image the Horsehead Nebula with the Celestron Origin
- How long to image the Horsehead Nebula with the Celestron Origin Mark II