Galaxy
M99 (M99)
In Coma Berenices (Com) • Magnitude 9.9 • 5.3 arcminutes
Open the free AstroPlanner with M99 pre-selected, scored against your telescope, location, and the live cloud forecast.
A grand-design face-on spiral galaxy in the Virgo Cluster showing one of the most complete and symmetrical spiral patterns in the nearby universe. One of its arms is noticeably stretched — visible proof that the Virgo Cluster's collective gravity can distort individual galaxies from millions of light-years away.
M99 at a glance
| Catalog IDs | M99, N 4254 |
| Type | Galaxy |
| Constellation | Coma Berenices (Com) |
| Right ascension | 12h 18m 47s |
| Declination | +14° 25' 12" |
| Apparent magnitude | 9.87 |
| Surface brightness | 13.6 mag/arcsec² |
| Angular size | 5.3 × 4.7 arcmin |
| Max altitude at 45°N | 59° |
| Best imaging months | Dec, Jan, Feb |
How to image M99
M99 sits in the constellation Coma Berenices at right ascension 12h 18m 47s and declination +14° 25' 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 a galaxy, M99 needs the darkest skies you can find: surface brightness, not just apparent magnitude, drives whether it will lift out of the gradient.