noun
astrophotography
Technical term for the photography of astronomical objects and the night sky.
彼は天体写真術に使う専用のカメラを買った。
He bought a specialized camera for astrophotography.
天体写真 is the resulting photograph, while 天体写真術 refers to the technique or art of astrophotography.
Compound of 天体 (astronomical body) + 写真 (photography) + 術 (technique, art).