IC 342 (also known as

Caldwell Caldwell may refer to: People * Caldwell (surname) * Caldwell (given name) * Caldwell First Nation, a federally recognized First Nation in southern Ontario, Canada Places Great Britain * Caldwell, Derbyshire, a hamlet * Caldwell, Ea ...

5) is an

intermediate spiral galaxy An intermediate spiral galaxy is a galaxy that is in between the classifications of a barred spiral galaxy and an unbarred spiral galaxy. It is designated as SAB in the galaxy morphological classification system devised by Gerard de Vaucouleur ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Camelopardalis Camelopardalis is a large but faint constellation of the northern sky representing a giraffe. The constellation was introduced in 1612 or 1613 by Petrus Plancius. Some older astronomy books give Camelopardalus or Camelopardus as alternative form ...

, located relatively close to the

Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...

. Despite its size and actual brightness, its location behind dusty areas near the

galactic equator The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way Galaxy, and the fundamental plane parallel to an ap ...

makes it difficult to observe, leading to the nickname "The Hidden Galaxy", though it can readily be detected even with binoculars. If the galaxy were not obscured, it would be visible by naked eye. The dust makes it difficult to determine its precise distance; modern estimates range from about 7 million

light-years A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astro ...

(Mly) to about 11 Mly. The galaxy was discovered by

William Frederick Denning William Frederick Denning (25 November 1848 – 9 June 1931) was a British amateur astronomer who achieved considerable success without formal scientific training. He is known for his catalogues of meteor radiants, observations of Jupiter's re ...

in 1892. It is one of the brightest in the

IC 342/Maffei Group The IC 342/Maffei Group (also known as the IC 342 Group or the Maffei 1 Group) corresponds to one or two galaxy groups close to the Local Group. The member galaxies are mostly concentrated around either IC 342 or Maffei 1, which would be the br ...

, one of the closest

galaxy group A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxi ...

s to the

Local Group The Local Group is the galaxy group that includes the Milky Way, where Earth is located. It has a total diameter of roughly , and a total mass of the order of . It consists of two collections of galaxies in a " dumbbell" shape; the Milky Way ...

Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects previously ...

first thought it to be in the Local Group, but it was later determined not to be a member. In 1935,

Harlow Shapley Harlow Shapley (November 2, 1885 – October 20, 1972) was an American astronomer, who served as head of the Harvard College Observatory from 1921–1952, and political activist during the latter New Deal and Fair Deal. Shapley used Cepheid var ...

found that it was wider than the full moon, and by angular size the third-largest spiral galaxy then known, smaller only than the

Andromeda Galaxy The Andromeda Galaxy is a barred spiral galaxy and is the nearest major galaxy to the Milky Way. It was originally named the Andromeda Nebula and is cataloged as Messier 31, M31, and NGC 224. Andromeda has a Galaxy#Isophotal diameter, D25 isop ...

(M31) and the

Triangulum Galaxy The Triangulum Galaxy is a spiral galaxy 2.73 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598. With the D25 isophotal diameter of , the Triangulum Galaxy is the third-largest me ...

(M33).Border Cities Star (Windsor, Ontario)
"Spiral Galaxy Third Biggest"
24 June 1935, p.8 (Modern estimates are more conservative, giving the apparent size as one-half to two-thirds the diameter of the full moon). It has an H II nucleus. The galaxy has a diameter of 75,000 light-years. In 2020, the galaxy

KKH 32 KKH may refer to: * the Karakoram Highway in northern Pakistan * KK Women's and Children's Hospital, formerly known as "Kandang Kerbau Hospital", a hospital in Singapore * Kongiganak Airport (IATA code: KKH), an airport in Alaska See also * kkh, ...

was identified as the first known satellite of IC 342 that is a

dwarf spheroidal galaxy A dwarf spheroidal galaxy (dSph) is a term in astronomy applied to small, low-luminosity galaxies with very little dust and an older stellar population. They are found in the Local Group as companions to the Milky Way and as systems that are c ...

. Unlike galaxies with large bulges such as the

, IC 342 has relatively few dwarf satellite galaxies. KKH 32 is located about 10.2 million light-years (3.12 megaparsecs) away, and has a diameter of about 4,300 light-years (1.32 kiloparsecs).

References

External links

NASA Astronomy Picture of the Day
– 22 December 2010

* {{DEFAULTSORT:IC 342 18920819 IC 0342 IC 0342 IC 0342 0342 02847 13826 005b 03419+6756 +11-05-003