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MACS0647-JD is a candidate, based on a photometric redshift estimate, for the farthest known galaxy from Earth at a redshift of about ''z'' = 10.7 - 11, equivalent to a light travel distance of 13.3 billion light-years (4 billion parsecs). If the distance estimate is correct, it formed 420 million years after the Big Bang. 〔 ==Details== JD refers to ''J-band Dropout''.〔 It is less than 600 light-years wide, and contains roughly a billion stars. The galaxy was discovered with the help of Cluster Lensing And Supernova survey with Hubble (CLASH), which uses massive galaxy clusters as cosmic telescopes to magnify distant galaxies behind them, an effect called gravitational lensing. Observations were recorded by the Wide Field Camera 3 on the Hubble Space Telescope,〔 with support from Spitzer Space Telescope.〔 The location of the galaxy is in the constellation Camelopardalis, which is also the location of the gravitational lensing cluster that helped discover this galaxy: MACSJ0647+7015 at ''z'' = 0.591. MACS0647-JD was announced in November 2012, but by the next month UDFj-39546284, which was previously thought to be ''z'' = 10.3, was said to be at ''z'' = 11.9,〔(Universe Today - Hubble Census Unveils Galaxies Shining Near Cosmic Dawn )〕 although more recent analyses have suggested the latter is likely to be at a lower redshift. Spectroscopic confirmation of the redshift of MACS0647-JD likely awaits the launch of the James Webb Space Telescope expected in 2018.〔http://scitechdaily.com/hubble-views-what-is-probably-the-most-distant-known-galaxy/〕 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「MACS0647-JD」の詳細全文を読む スポンサード リンク
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