Emission nebula
Crescent Nebula (NGC6888)
In Cygnus (Cyg) • Magnitude 7.4 • 20 arcminutes
Open the free AstroPlanner with Crescent Nebula pre-selected, scored against your telescope, location, and the live cloud forecast.
A Wolf-Rayet wind-blown bubble in Cygnus, intense in OIII.
Crescent Nebula at a glance
| Catalog IDs | N 6888, C 27 |
| Type | Emission nebula |
| Constellation | Cygnus (Cyg) |
| Right ascension | 20h 12m 07s |
| Declination | +38° 21' 00" |
| Apparent magnitude | 7.40 |
| Surface brightness | 14.5 mag/arcsec² |
| Angular size | 20.0 × 10.0 arcmin |
| Max altitude at 45°N | 83° |
| Best imaging months | Jun, Jul, Aug, Sep |
How to image Crescent Nebula
Crescent Nebula sits in the constellation Cygnus at right ascension 20h 12m 07s and declination +38° 21' 00". To frame and integrate it well, AstroPlanner will compute the optimal moonless window for tonight from your location, the field-of-view fit against your sensor and focal length, the suggested total integration time given your aperture and sky Bortle class, and a cloud-aware schedule that drops it from the plan if your nearest cloud forecast spike overlaps the best altitude window. As an emission nebula, Crescent Nebula responds very well to dual-narrowband filters under city skies.