Planetary nebula
Bow-Tie Nebula (NGC40)
In Cepheus (Cep) • Magnitude 11.9 • 0.8 arcminutes
Open the free AstroPlanner with Bow-Tie Nebula pre-selected, scored against your telescope, location, and the live cloud forecast.
Planetary nebula in Cepheus with a faint bow-tie shape.
Bow-Tie Nebula at a glance
| Catalog IDs | N 40 |
| Type | Planetary nebula |
| Constellation | Cepheus (Cep) |
| Right ascension | 00h 13m 01s |
| Declination | +72° 31' 19" |
| Apparent magnitude | 11.90 |
| Surface brightness | 20.0 mag/arcsec² |
| Angular size | 0.8 × 0.8 arcmin |
| Max altitude at 45°N | 62° |
| Best imaging months | Aug, Sep, Oct, Nov |
How to image Bow-Tie Nebula
Bow-Tie Nebula sits in the constellation Cepheus at right ascension 00h 13m 01s and declination +72° 31' 19". 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 a planetary nebula, Bow-Tie Nebula typically appears small and intense, so a long focal length and OIII or Ha narrowband filters bring out structure.