Emission nebula
Thor’s Helmet (NGC2359)
In Canis Major (CMa) • Magnitude 11.5 • 10 arcminutes
Open the free AstroPlanner with Thor’s Helmet pre-selected, scored against your telescope, location, and the live cloud forecast.
A bubble-shaped Wolf-Rayet emission nebula in Canis Major.
Thor’s Helmet at a glance
| Catalog IDs | N 2359 |
| Type | Emission nebula |
| Constellation | Canis Major (CMa) |
| Right ascension | 07h 22m 59s |
| Declination | -13° 13' 12" |
| Apparent magnitude | 11.50 |
| Surface brightness | 14.0 mag/arcsec² |
| Angular size | 10.0 × 8.0 arcmin |
| Max altitude at 45°N | 32° |
| Best imaging months | Dec, Jan, Feb, Mar |
How to image Thor’s Helmet
Thor’s Helmet sits in the constellation Canis Major at right ascension 07h 22m 59s and declination -13° 13' 12". 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, Thor’s Helmet responds very well to dual-narrowband filters under city skies.