Gioiello (lit. Jewel in Italian; officially XDCP J0044.0-2033) is a massive galaxy cluster located 2.9 Gpc away in the southern constellation of Cetus. Its discovery was announced late December 2014. Observations by Chandra X-ray Observatory has shown that the total mass of the cluster is 400 trillion solar masses. The study also implies that the age of the cluster is 800 Million years.
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Gioiello (galaxy cluster) Wikipedia(Text) CC BY-SA