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IC 342 (IC=''Index Catalogue'')(also known as Caldwell 5) is an intermediate spiral galaxy in the constellation Camelopardalis. The galaxy is near the galactic equator where dust obscuration makes it a difficult object for both amateur and professional astronomers to observe,〔(【引用サイトリンク】 work=Results for IC 342 )〕 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.〔 IC 342 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.〔SEDS (IC 342 ).〕 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 that the full moon.〔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.〔 〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「IC 342」の詳細全文を読む スポンサード リンク
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