sidereal

/sa‍ɪdˈi‍əɹɪə‍l/

/saɪdˈiəɹɪəl/

sidereal

(of divisions of time) determined by daily motion of the stars

antonyms : civil

of or relating to the stars or constellations

Examples

1. This calculates the mean sidereal month.

2. Well, 23 hours and 56 minutes is actually equal to one sidereal day.

3. It's the large prime factor of 254, the number of sidereal months in a 19-year metonic cycle.

4. Remarkably, the ancient Babylonian astronomers knew of this difference between the sidereal and the anomalistic month, as did the ancient Greeks.