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Hipparchus satellite

British  

noun

  1. an astronometric satellite launched in 1989 by the European Space Agency that measured the position, proper motion, and brightness of 118 218 stars down to 12th magnitude and the magnitude and colour of a million stars down to 10th magnitude

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of Hipparchus satellite

after Hipparchus , Greek astronomer (2nd century bc