noun
star map; celestial chart
A map of the night sky showing stars, constellations, and other celestial objects. Used in astronomy and stargazing.
彼は天体図を見ながら星座を探した。
He looked for constellations while consulting a star map.
Compound of 天体 (celestial body) and 図 (map, chart). The reading ず for 図 is a common rendaku form.