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Meaning of siderostat

sid•er•o•stat

Pronunciation: (sid'ur-u-stat"), [key]
— n.
  1. 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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.