Emission nebula
Trifid Nebula (M20)
In Sagittarius (Sgr) • Magnitude 8.5 • 28 arcminutes
Open the free AstroPlanner with Trifid Nebula pre-selected, scored against your telescope, location, and the live cloud forecast.
A visually stunning nebula divided into three bright lobes by dark dust lanes — the name Trifid literally means "divided into three." It is one of the very few objects that simultaneously shows emission nebula (red-pink), reflection nebula (blue), and dark nebula all in a single field of view.
Trifid Nebula at a glance
| Catalog IDs | M20, N 6514 |
| Type | Emission nebula |
| Constellation | Sagittarius (Sgr) |
| Right ascension | 18h 02m 35s |
| Declination | -23° 01' 48" |
| Apparent magnitude | 8.50 |
| Surface brightness | 14.0 mag/arcsec² |
| Angular size | 28.0 × 27.0 arcmin |
| Max altitude at 45°N | 22° |
| Best imaging months | Mar, Apr, May |
How to image Trifid Nebula
Trifid Nebula sits in the constellation Sagittarius at right ascension 18h 02m 35s and declination -23° 01' 48". 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, Trifid Nebula responds very well to dual-narrowband filters under city skies.