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 (ˌsideroˈstatic)
adjective
Word origin
C19: from sidero-, from Latin sidus a star + -stat, on the model of heliostat