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Glite Dictionary
sidereal time

sidereal time

9.9
Time kept by the position of stars to track Earth's rotation
  • noun
  • /saɪˈdɪəriəl taɪm/
  • Specialized
translation icon : tiempo sidéreo
  • Astronomers use sidereal time to accurately track the positions of stars in the night sky.

Examples

  • At that moment, my local sidereal time would match the right ascension of that star.

    Academic text (2002)

  • Following through with the experiment, now that I had a clock synchronized to GMT, I could calculate the sidereal time at Greenwich.

    Academic text (2002)

  • To align the telescope, he had to convert the standard time to sidereal time.

  • Understanding sidereal time is essential for observing celestial events accurately.

Synonyms

LST
vssidereal time
  • Specialized
9.9

The time that shows the Earth's rotation relative to the stars

is the full term for star-based time not limited to location

Surface Forms

sidereal time singular
sidereal times plural

Morphology

sidereal + time

The noun phrase is compositionally built from 'sidereal' (relating to the stars) + 'time', so a learner who knows both constituents can infer it means 'time measured by/according to the stars'. The precise astronomical distinction from solar time is technical, but the core meaning is transparently derived from the parts and follows a common modifier+noun pattern.

Etymology

The term sidereal time comes from the simple idea of using the stars as a clock. Astronomers watch a star and note when it comes back to the same place, so sidereal time measures how the Earth turns compared with the 'stars' rather than the 'sun'.