coelostat

[ see-luh-stat ]
/ ˈsi ləˌstæt /

noun Astronomy.

an apparatus consisting of a mirror driven by clockwork, used to enable a fixed telescope to keep the same area of sky in its field of view by compensating for the apparent rotation of the celestial sphere.
Compare siderostat.

Origin of coelostat

1895–1900; coelo- (for Latin caeli-, combining form of caelum sky) + -stat

Example sentences from the Web for coelostat

  • It will be laid comfortably flat on the ground, and the rays of light reflected into it by a coelostat.

    Astronomical Discovery |Herbert Hall Turner

British Dictionary definitions for coelostat

coelostat
/ (ˈsiːləˌstæt) /

noun

an astronomical instrument consisting of a plane mirror mounted parallel to the earth's axis and rotated about this axis once every two days so that light from a celestial body, esp the sun, is reflected onto a second mirror, which reflects the beam into a telescope Compare siderostat

Word Origin for coelostat

C19 coelo-, from Latin caelum heaven, sky + -stat