IC 342

{{Short description|Spiral galaxy in the constellation Camelopardalis}}

{{Infobox Galaxy

| name = IC 342

| image = Euclid’s view of spiral galaxy IC 342 ESA25170723.jpg

| caption = Euclid telescope image of the IC 342 galaxy

| epoch = J2000

| ra = {{RA|03|46|48.5028}}

| dec = {{DEC|+68|05|46.924}}

| constellation name = Camelopardalis

| z = 31 ± 3 km/s

| dist_ly = 10.7 ± 0.9 Mly (3.3 ± 0.3 Mpc){{cite journal

|author1=I. D. Karachentsev |author2=V. E. Karachentseva |author3=W. K. Hutchmeier |author4=D. I. Makarov | title=A Catalog of Neighboring Galaxies

| journal=Astronomical Journal

| date=2004

| volume=127

| issue=4

| pages=2031–2068

| bibcode=2004AJ....127.2031K

| doi=10.1086/382905| doi-access=free

}}{{cite journal

|author1=Karachentsev, I. D. |author2=Kashibadze, O. G. | title=Masses of the local group and of the M81 group estimated from distortions in the local velocity field

| journal=Astrophysics

| date=2006

| volume=49

| issue=1

| pages=3–18

| bibcode=2006Ap.....49....3K

| doi=10.1007/s10511-006-0002-6 |s2cid=120973010 }}

| type = SAB(rs)cd

| appmag_v = 9.1

| size_v = 21.4{{prime}} × 20.9{{prime}}

| size = ~150,000 ly (45.62 kpc) (estimated)

| stars = 100 billion

| notes =

| names = {{odlist | UGC= 2847 | PGC= 13826 | C= 5 | CGCG= 305-002 | MCG= +11-05-003 | IRAS= 03419+6756}}

}}

IC 342 (also known as Caldwell 5) is an intermediate spiral galaxy in the constellation Camelopardalis, located relatively close to the Milky Way. Despite its size and actual brightness, its location behind dusty areas near the galactic equator makes it difficult to observe, leading to the nickname "The Hidden Galaxy",{{cite web|title=Hubble's Hidden Galaxy|url=https://www.spacetelescope.org/images/potw1727a/|website=www.spacetelescope.org|access-date=3 July 2017|archive-date=20 December 2020|archive-url=https://web.archive.org/web/20201220131824/https://www.spacetelescope.org/images/potw1727a/|url-status=dead}}{{cite web

| title=NASA/IPAC Extragalactic Database

| work=Results for IC 342

| url=http://nedwww.ipac.caltech.edu/

| access-date=2006-11-01

}} though it can readily be detected even with binoculars.{{cite book

| last=O'Meara

| first=Stephen James

| title=The Caldwell Objects

| date=2002

| publisher=Cambridge University Press

| isbn=0-933346-97-2

| pages=30–32

}} 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 (Mly){{Cite APOD

| title=Hidden Galaxy IC 342

| date=22 December 2010

|access-date=28 January 2013

}} to about 11 Mly. The galaxy was discovered by William Frederick Denning in 1892.{{cite journal|title=New nebula|bibcode=1893AstAp..12..189D|author=Denning, W. F.|journal=Astronomy and Astro-Physics|date=1893|volume=12|page=189}} It is one of the brightest in the IC 342/Maffei Group, one of the closest galaxy groups to the Local Group. Edwin Hubble first thought it to be in the Local Group, but it was later determined not to be a member.SEDS [http://spider.seds.org/spider/LG/i0342.html IC 342]. {{webarchive |url=https://web.archive.org/web/20070102030726/http://www.seds.org/~spider/spider/LG/i0342.html |date=January 2, 2007 }}

In 1935, Harlow Shapley 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 (M31) and the Triangulum Galaxy (M33).Border Cities Star (Windsor, Ontario), [https://news.google.com/newspapers?id=OP8-AAAAIBAJ&sjid=oU0MAAAAIBAJ&pg=5836,2330915 "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.

{{cite journal

| last1 = Ho | first1 = Luis C.

| last2 = Filippenko | first2 = Alexei V.

| last3 = Sargent | first3 = Wallace L. W.

| title = A Search for 'Dwarf' Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies

| date = 1997

| periodical = Astrophysical Journal Supplement

| volume = 112 | issue = 2

| pages = 315–390

| arxiv=astro-ph/9704107

| bibcode=1997ApJS..112..315H

| doi = 10.1086/313041

| s2cid = 17086638

}} In 2020, the galaxy KKH 32 was identified as the first known satellite of IC 342 that is a dwarf spheroidal galaxy. Unlike galaxies with large bulges such as the Andromeda Galaxy, 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).{{cite journal|doi=10.1051/0004-6361/202037993|title=KKH 22, the first dwarf spheroidal satellite of IC 342|year=2020|last1=Karachentsev|first1=Igor D.|last2=Makarova|first2=Lidia N.|last3=Tully|first3=R. Brent|last4=Anand|first4=Gagandeep S.|last5=Rizzi|first5=Luca|last6=Shaya|first6=Edward J.|last7=Afanasiev|first7=Viktor L.|s2cid=218538458|journal=Astronomy & Astrophysics|volume=638|pages=A111|arxiv=2005.03132|bibcode=2020A&A...638A.111K}}

File:Hubble's Hidden Galaxy.jpg