sidereal
adjUK /saɪˈdɪə.ɹi.əl/ · US /saɪˈdɪɚ.i.əl/
Etymology From Latin sīdereus + -al (cf. Latin sīderālis), from sīdus (“star, constellation”), of unknown ultimate origin, likely a substrate language such as Pre-Greek.
1
Of or relating to the stars.
- These fringes of lamplight, struggling up through smoke and thousandfold exhalation, some fathoms into the ancient reign of Night, what thinks Boötes of them, as he leads his Hunting-Dogs over the Zenith in their leash of sidereal fire?1831, Thomas Carlyle, “Reminiscences”, in Sartor Resartus: The Life and Opinions of Herr Teufelsdröckh. […], London: Chapman and Hall, […], →OCLC, 1st book, page 14:
- The field of sidereal astronomy, therefore, was virtually untrodden when, shortly after the beginning of his telescopic work, Herschel began his first review of the heavens.1919, Hector Macpherson, “Chapter V”, in S.Chapman (series editor), editor, Men of Science: Herschel:
2
Astronomy, Natural sciences Relating to a measurement of time relative to the position of the stars.
- Then, from a sufficient number of observations of synodic periods to give their mean, we obtain the sidereal period, or period with reference to the stars.1903, Percival Lowell, “Chapter I”, in The Solar System:
3
Astronomy, Natural sciences Relating to a measurement of time relative to the point of the vernal equinox.
- Derived terms
- intersidereal, nonsidereal, sidereal astrology, sidereal clock, sidereal day, sidereal hour, sidereal hour angle, siderealize, sidereally, sidereal midnight, sidereal minute, sidereal month, sidereal noon, sidereal orbital period, sidereal period, sidereal pole, sidereal rotation period, sidereal second, sidereal table, sidereal time, sidereal year