noun
celestial sphere; the heavens
Astronomical term for the imaginary sphere on which celestial bodies appear to lie. Also used poetically for the sky or heavens.
天球上の星の位置を観測する。
Observe the positions of stars on the celestial sphere.
夜空を見上げると、無数の星が天球に散らばっているように見
Looking up at the night sky, countless stars appear scattered across the celestial sphere.