Planetary nebula
NGC 2440 (NGC2440)
In Puppis (Pup) • Magnitude 9.4 • 0.3 arcminutes
Open the free AstroPlanner with NGC 2440 pre-selected, scored against your telescope, location, and the live cloud forecast.
Compact planetary nebula in Puppis.
NGC 2440 at a glance
| Catalog IDs | N 2440 |
| Type | Planetary nebula |
| Constellation | Puppis (Pup) |
| Right ascension | 07h 41m 55s |
| Declination | -18° 12' 31" |
| Apparent magnitude | 9.40 |
| Surface brightness | 15.2 mag/arcsec² |
| Angular size | 0.3 × 0.3 arcmin |
| Max altitude at 45°N | 27° |
| Best imaging months | Dec, Jan, Feb |
How to image NGC 2440
NGC 2440 sits in the constellation Puppis at right ascension 07h 41m 55s and declination -18° 12' 31". 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, NGC 2440 typically appears small and intense, so a long focal length and OIII or Ha narrowband filters bring out structure.