Sh2-129 — Flying Bat Nebula
HII Region in Cepheus
About
Sh2-129 is a big cloud of glowing hydrogen in Cepheus, roughly 1,700 light-years from us. Inside it hides Ou 4, the Squid Nebula, a bipolar outflow that the triple star HD 202214 is believed to power.
Imaging tips
- Spans about 150′, so 160–270 mm on APS-C or 250–410 mm on full frame fits the whole nebula in the frame.
- An emission nebula, so narrowband suits it. One imager used a Ha/OIII dual-band filter for about 50 hours of 5-minute subs, plus about 3 hours of 60 s broadband, from a Bortle 6 site.
- Ou 4, the Squid Nebula, lies inside the same region, so a wide frame can take in both.
- Best around July and August, peaking near 80° altitude from 50°N.
Facts
- Size
- 150′
- Magnitude
- —
- Coordinates
- RA 21h 11.8m, Dec +59° 57′
- Framing, APS-C
- 160–270 mm
- Framing, full frame
- 250–410 mm
- Best months
- Jul, Aug
- Peak altitude
- 80° from 50°N, 65° from 35°N