天体光谱学 tiāntǐguāngpǔxué astronomical spectroscopy Origin Definitions Defs Strokes Stroke Words Sentences Sents 天体 天體 tiāntǐ noun celestial body General term for objects in the universe, including stars, planets, satellites, comets, meteors, and cosmic dust光谱学 光譜學 guāngpǔxué spectroscopy