Galaxy
Leo Triplet (M66)
In Leo (Leo) • Magnitude 8.9 • 9.0 arcminutes
Open the free AstroPlanner with Leo Triplet pre-selected, scored against your telescope, location, and the live cloud forecast.
The brightest of the Leo Triplet, with noticeably asymmetric spiral arms pulled out of shape by the gravitational tug-of-war with its neighbours M65 and NGC 3628. Its distorted appearance is a living record of hundreds of millions of years of gravitational wrestling between nearby galaxies.
Leo Triplet at a glance
| Catalog IDs | M66, N 3627 |
| Type | Galaxy |
| Constellation | Leo (Leo) |
| Right ascension | 11h 20m 13s |
| Declination | +12° 58' 48" |
| Apparent magnitude | 8.90 |
| Surface brightness | 13.2 mag/arcsec² |
| Angular size | 9.0 × 4.0 arcmin |
| Max altitude at 45°N | 58° |
| Best imaging months | Dec, Jan, Feb |
How to image Leo Triplet
Leo Triplet sits in the constellation Leo at right ascension 11h 20m 13s and declination +12° 58' 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 a galaxy, Leo Triplet needs the darkest skies you can find: surface brightness, not just apparent magnitude, drives whether it will lift out of the gradient.