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[sid-er-uh-stat] /ˈsɪd ər əˌstæt/
a telescopic device for reflecting the light of a star in a constant direction, the chief component of which is a plane mirror turned by a clock mechanism to correct for the rotation of the earth.
Origin of siderostat
First recorded in 1875-80; sidero-2 + -stat
Related forms
siderostatic, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
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Examples from the Web for siderostat
Historical Examples
  • The telescope was housed at the Exhibition in a long gallery pointing due north and south, the siderostat at the north end.

    The Romance of Modern Invention Archibald Williams
  • The siderostat, twenty-seven feet high, and as many in length, weighed forty-five tons.

    The Romance of Modern Invention Archibald Williams
  • The movable portion of the roof of the building had been slid back, and the mirror of the siderostat stood bared to the sky.

    The Romance of Modern Invention Archibald Williams
British Dictionary definitions for siderostat


an astronomical instrument consisting essentially of a plane mirror driven about two axes so that light from a celestial body, esp the sun, is reflected along a constant direction for a long period of time See also heliostat Compare coelostat
Derived Forms
siderostatic, adjective
Word Origin
C19: from sidero-, from Latin sidus a star + -stat, on the model of heliostat
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
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