写しゃ真しん等とう級きゅう

noun

photographic magnitude

Technical term in astronomy; refers to the brightness of a celestial object as measured on a photographic plate, which may differ from visual magnitude.

• 写しゃ真しん等とう級きゅうは、天てん体たいの明あかるさを写しゃ真しん乾かん板ぱんで測そく定ていした値あたいです。

  Photographic magnitude is a value that measures the brightness of a celestial object on a photographic plate.