coelostat

• 一种装有可动镜和固定镜的光学装置，用于跟踪天体并把它发出的光反射到望远镜中。

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.

   定天镜

   • 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.