coelostat

• Instrument optique composé d'un miroir mobile et d'un miroir fixe, utilisé pour suivre le mouvement d'un corps céleste et diriger sa lumière vers un télescope.

An optical device with a movable and a fixed mirror, used to track the path of a celestial body and reflect its light into a telescope.

1. Optical device for celestial trackingC2formalscientific

   An optical instrument that uses a movable mirror and a fixed mirror to reflect the light from a celestial body into a stationary telescope, compensating for the Earth's rotation.

   Coélostat

   • The astronomer adjusted the coelostat to track the sun's path across the sky.
   • A coelostat is essential for long-exposure solar photography.
   • The observatory's coelostat allowed them to study the star's spectrum continuously.