IC 342 (also known as Caldwell 5) is an intermediate spiral galaxy in the constellation Camelopardalis. In the Catalogue of Named Galaxies, it is called Stellivelatus Camelopardalis, or the star-veiled galaxy.
The galaxy is near the galactic equator where dust obscuration makes it a difficult object for both amateur and professional astronomers to observe, though it can readily be detected even with binoculars.
The dust of the Milky Way makes it difficult to determine the precise distance; modern estimates range from about 7 Mly to about 11 Mly.
The galaxy is one of the brightest two galaxies in the IC 342/Maffei Group of galaxies, one of the galaxy groups that is closest to the Local Group.
The galaxy was discovered by William Frederick Denning in 1895. Edwin Hubble first thought it to be in the Local Group, but later it was demonstrated that the galaxy is outside the Local Group.
It has an H II nucleus.
In 1935, Harlow Shapley declared that this galaxy was the third-largest spiral galaxy by angular size then known, smaller only than the Andromeda Galaxy (M31) and the Triangulum Galaxy (M33), being wider than the full moon. (Modern estimates are more conservative, giving the apparent size as one-half to two-thirds the diameter of the full moon).
The spiral galaxy IC 342 shines prominently in this image from the Hubble Space Telescope, but viewing it in the night sky from Earth is much more challenging. In fact, it’s nicknamed the Hidden Galaxy.