NGC 4236 is a large, edge-on barred spiral galaxy spanning over 12 arc minutes in apparent length, making it a rewarding wide-field target for astrophotographers. With an apparent magnitude of 10.08, this galaxy is bright enough for modest amateur telescopes and camera setups, though its low surface brightness of 22.6 mag/arcsec² demands dark skies and careful integration time to reveal its faint spiral structure. The galaxy’s physical diameter of 52,200 light-years makes it a substantial member of the nearby galactic neighborhood. Its negative radial velocity of -8 km/s indicates that NGC 4236 is approaching us, a relatively uncommon feature among galaxies beyond our immediate Local Group.
Names and Catalog numbers
- C 3 (Caldwell 3)
- NGC 4236
- UGC 7306
- PGC 39346
Position and the cosmic neighborhood
NGC 4236 resides in the northern circumpolar constellation Draco, positioned at right ascension 12h 16m 42s and declination +69° 27′ 45″. Its high declination makes it an excellent target for northern hemisphere observers, remaining visible throughout much of the year. The galaxy’s elongated form stretches more than 12 arc minutes across the sky, comparable to nearly half the apparent diameter of the full Moon, though its extended nature and faint surface brightness require dark skies to capture effectively. At a distance of 14.4 million light-years, NGC 4236 lies well beyond our Local Group but remains part of the relatively nearby universe, offering astrophotographers a chance to image intricate spiral features in a large, face-on perspective when using appropriate focal lengths.
Nice to Know
- NGC 4236 is one of the largest apparent-size spiral galaxies visible in the night sky, with an angular extent of 12.5 by 3 arc minutes—significantly larger than many popular deep-sky targets, making it ideal for wide-field imaging setups.
- The galaxy’s extremely low surface brightness of 22.6 mag/arcsec² presents a challenging but rewarding imaging target, requiring multiple hours of integration under dark skies to bring out the delicate spiral arms and dust lanes.
- With a negative radial velocity of -8 km/s, NGC 4236 is moving toward our Milky Way rather than receding, a relatively rare property that distinguishes it from the vast majority of galaxies showing cosmological redshift.
- Also cataloged as Caldwell 3, NGC 4236 earned its place in Patrick Moore’s Caldwell Catalog as an overlooked gem suitable for amateur observation, complementing the more famous Messier objects with targets of similar visual appeal.
Brightness, distance and size
The object has an apparent magnitude of 10.1 mag, it lies about 14.4 million light-years from Earth and spans roughly 52,200 light-years across. On the sky it appears about 12′ × 3.0′ in size.
