Narrowband · autumn 2026
Emission nebulae in the light of hydrogen, oxygen and sulphur. Three targets and 12 h 45 min of exposure.
NGC 281 · Cassiopeia
Hubble palette: sulphur red, hydrogen green, oxygen blue.
An emission nebula about 9,500 light years away, lit by the young cluster IC 1590 at its centre. The dark lanes that make the mouth are dust in front of the glowing gas. In the Hubble palette, sulphur shows as the gold rim and oxygen as the blue core.
| Ha | 15 × 5 min | 1 h 15 min |
|---|---|---|
| Oiii | 26 × 5 min | 2 h 10 min |
| Sii | 34 × 5 min | 2 h 50 min |
| Total | 75 subs | 6 h 15 min |
4–5 and 5–6 November 2026
IC 405 · Auriga
Hubble palette: sulphur red, hydrogen green, oxygen blue.
Gas and dust lit by AE Aurigae, the bright star near the centre, a runaway star thrown out of the Orion region a few million years ago. Hydrogen dominates and there is little oxygen, so the HOO version is nearly all red.
| Ha | 13 × 5 min | 1 h 05 min |
|---|---|---|
| Oiii | 15 × 5 min | 1 h 15 min |
| Sii | 33 × 5 min | 2 h 45 min |
| Total | 61 subs | 5 h 05 min |
4–5 and 5–6 November 2026
NGC 7380 · Cepheus
Hubble palette: sulphur red, hydrogen green, oxygen blue.
A young open cluster still wrapped in the cloud it formed from. The wizard is the dark, hooded silhouette along the lower edge. This is a first pass from a single night, so it is noisier than the others.
| Ha | 4 × 5 min | 20 min |
|---|---|---|
| Oiii | 6 × 5 min | 30 min |
| Sii | 7 × 5 min | 35 min |
| Total | 17 subs | 1 h 25 min |
5–6 November 2026
Sky-Watcher ED80, 0.85× reducer, 522 mm f/6.5
ZWO ASI294MM Pro, bin 2 (1.83″/px), gain 120, −10 °C
ZWO AM5N on a permanent pier
Ha, Oiii and Sii narrowband in a ZWO EFW
ASIAIR Plus, 300 s subs, dithered, autofocus on the EAF
Siril 1.4: darks, flats and flat-darks, registration and stacking, sky-glow removal, noise reduction, Ha as luminance
Images are oriented with east on the left, as the sky appears, and north within about 25° of up. The compass on each shows the exact direction. Click an image to see it larger.