sidereal time

sidereal time

n.

Time based on the rotation of the earth with reference to the background of stars.

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sidereal time

Time based on the rotation of the Earth with respect to the background of fixed stars. Astronomers generally use sidereal time rather than solar time because it is better suited to observations beyond the solar system. A sidereal day is the time required for one complete rotation of the Earth on its axis with respect to a fixed star. It is an unvarying unit equal to 23 hours, 56 minutes, 4.09 seconds of solar time. A sidereal month is the average period of revolution of the Moon around the Earth with respect to a fixed star, equal to 27 days, 7 hours, 43 minutes of solar time. A sidereal year is the time required for one complete revolution of the Earth around the Sun with respect to a fixed star, equal to 365 days, 6 hours, 9 minutes, 9.54 seconds of solar time. Compare solar time.

Thesaurus

Noun

1.

sidereal time - measured by the diurnal motion of stars cosmic time - the time covered by the physical formation and development of the universe sidereal day, day - the time for one complete rotation of the earth relative to a particular star, about 4 minutes shorter than a mean solar day sidereal year - the time for the earth to make one complete revolution around the sun, relative to the fixed stars sidereal hour - 1/24 of a sidereal day sidereal month - period between successive conjunctions with a star, 27.322 days