主しゅ鏡きょう

noun

primary mirror; main mirror

Technical term in astronomy for the main light-gathering mirror of a reflecting telescope.

• 反はん射しゃ望ぼう遠えん鏡きょうの主しゅ鏡きょうは、光ひかりを集あつめる役やく割わりを果はたす。

  The primary mirror of a reflecting telescope serves to collect light.