Pacman Nebula
NGC 281 · Emission nebula in Cassiopeia
- Magnitude
- 7.4
- Size
- 35′ × 30′
- Effective surface brightness
- 22.5 mag/arcsec²
- Best months
- Sep, Oct, Nov
- Declination
- +57°
- Filter
- Dual-band recommended
A bright emission nebula with a dark lane biting into it. Compact, bright, and excellent with a dual-band filter from suburban skies.
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 | 81% | 1 h 10 min420 subs | 1 h 22 min495 subs | 2 h 17 min820 subs |
| ZWO Seestar S50 Pro10 s subs, dual-band | 42% | 1 h 20 min479 subs | 1 h 33 min560 subs | 2 h 32 min912 subs |
| ZWO Seestar S3010 s subs, dual-band | 49% | 1 h 27 min523 subs | 1 h 39 min597 subs | 2 h 34 min923 subs |
| ZWO Seestar S30 Pro10 s subs, dual-band | 26% | 1 h 27 min522 subs | 1 h 41 min607 subs | 2 h 43 min977 subs |
| DwarfLab DWARF 315 s subs, dual-band | 35% | 1 h 17 min308 subs | 1 h 36 min385 subs | 3 h720 subs |
| DwarfLab DWARF mini15 s subs, dual-band | 49% | 1 h 08 min274 subs | 1 h 21 min324 subs | 2 h 15 min541 subs |
| DwarfLab Draco30 s subs, dual-band | 47% | 54 min109 subs | 1 h 04 min129 subs | 1 h 50 min220 subs |
| DwarfLab DWARF II15 s subs | 33% | 4 h 34 min1,097 subs | 6 h 27 min1,548 subs | 15 h3,516 subs |
| Vaonis Vespera II10 s subs | 41% | 1 h362 subs | 1 h 41 min605 subs | 4 h 38 min1,669 subs |
| Vaonis Vespera Pro10 s subs | 36% | 2 h 29 min897 subs | 3 h 55 min1,408 subs | 10 h3,643 subs |
| Vaonis Vespera 310 s subs | 40% | 57 min343 subs | 1 h 36 min576 subs | 4 h 26 min1,597 subs |
| Vaonis Vespera Pro 210 s subs | 35% | 2 h 21 min845 subs | 3 h 43 min1,336 subs | 9 h 40 min3,483 subs |
| Unistellar eQuinox 24 s subs | 1.0× frame | 1 h 25 min1,270 subs | 1 h 50 min1,649 subs | 3 h 40 min3,305 subs |
| Unistellar Odyssey4 s subs | 1.0× frame | 7 h 36 min6,843 subs | 9 h 08 min8,222 subs | 16 h14,250 subs |
| Celestron Origin10 s subs | 68% | 14 min84 subs | 25 min153 subs | 1 h 16 min455 subs |
| Celestron Origin Mark II10 s subs | 78% | 17 min103 subs | 34 min202 subs | 1 h 46 min637 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 Pacman Nebula with the ZWO Seestar S50
- How long to image the Pacman Nebula with the ZWO Seestar S50 Pro
- How long to image the Pacman Nebula with the ZWO Seestar S30
- How long to image the Pacman Nebula with the ZWO Seestar S30 Pro
- How long to image the Pacman Nebula with the DwarfLab DWARF 3
- How long to image the Pacman Nebula with the DwarfLab DWARF mini
- How long to image the Pacman Nebula with the DwarfLab Draco
- How long to image the Pacman Nebula with the DwarfLab DWARF II
- How long to image the Pacman Nebula with the Vaonis Vespera II
- How long to image the Pacman Nebula with the Vaonis Vespera Pro
- How long to image the Pacman Nebula with the Vaonis Vespera 3
- How long to image the Pacman Nebula with the Vaonis Vespera Pro 2
- How long to image the Pacman Nebula with the Unistellar eQuinox 2
- How long to image the Pacman Nebula with the Unistellar Odyssey
- How long to image the Pacman Nebula with the Celestron Origin
- How long to image the Pacman Nebula with the Celestron Origin Mark II