C27 — Crescent Nebula
Emission Nebula in Cygnus
About
NGC 6888, the Crescent Nebula, an emission nebula in Cygnus about 5,000 light-years away. The Wolf-Rayet star WR 136 at its centre shaped it: the star's present wind is crashing into material it threw off in an earlier phase.
Imaging tips
- At 1350–2240 mm on APS-C the nebula fills a third to half of the frame, so choose a long focal length.
- An emission nebula: narrowband filters (Hα, OIII or a dual-band) suit it.
- Wikipedia describes it as bright by imaging standards, though it is visually faint.
- Best around July and August; it climbs to about 78° altitude from 50°N.
Facts
- Size
- 18′ × 13′
- Magnitude
- —
- Coordinates
- RA 20h 12.2m, Dec +38° 21′
- Framing, APS-C
- 1350–2240 mm
- Framing, full frame
- 2060–3440 mm
- Best months
- Jul, Aug
- Peak altitude
- 78° from 50°N, 87° from 35°N