Try Our Apps


90s Slang You Should Know

sidereal time

noun, Astronomy.
time measured by the diurnal motion of stars. A sidereal day is about four minutes shorter than a solar day, with hours, minutes, and seconds all proportionally shorter.
Origin of sidereal time
First recorded in 1805-15 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
Cite This Source
Examples from the Web for sidereal time
Historical Examples
  • By looking at the diagram furnished you when we were talking of sidereal time, all this becomes perfectly clear.

    Lectures in Navigation Ernest Gallaudet Draper
  • This is sidereal time which agrees with mean time on March 22d, and gains on the latter at the rate of two hours a month.

    A Field Book of the Stars William Tyler Olcott
  • The sidereal time at any moment is the right ascension of the hour circle which at that moment coincides with the meridian.

    A Text-Book of Astronomy George C. Comstock
  • When the hour circle passing through Sirius coincides with the meridian, the sidereal time is 6h.

    A Text-Book of Astronomy George C. Comstock
  • He assigns the Parthenon to a hill of ages, and the temples of Upper Egypt to sidereal time.

    The Colour of Life Alice Meynell
  • Having set the clock approximately to sidereal time, observe one or two more stars in the same way as above.

    A Text-Book of Astronomy George C. Comstock
  • sidereal time was determined by observing transits of stars over a meridian line actually laid out upon the ground, etc.

    A Text-Book of Astronomy George C. Comstock
  • If the clock gains or loses with respect to sidereal time, take this into account in the value of U.

    A Text-Book of Astronomy George C. Comstock
  • After understanding its construction, extract the sidereal time at Noon for the day of your birth and refer to the next chapter.

    Astrology Sepharial
  • One can not tell off-hand whether 10 hours, sidereal time, falls in the day or in the night.

    A Text-Book of Astronomy George C. Comstock
British Dictionary definitions for sidereal time

sidereal time

time based upon the rotation of the earth with respect to the distant stars, the sidereal day being the unit of measurement See also sidereal day
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
sidereal time in Science
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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for sidereal time

Few English speakers likely know this word

Word Value for sidereal

Scrabble Words With Friends

Nearby words for sidereal time