precession of the equinoxes

American  

noun

1. the earlier occurrence of the equinoxes in each successive sidereal year because of the slow retrograde motion of the equinoctial points along the ecliptic, caused by the precession of the earth's axis of rotation; a complete precession of the equinoxes requires about 25,800 years.

2. the resulting drift of celestial coordinates with respect to the positions of celestial objects.

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precession of the equinoxes British  

noun

1. the slightly earlier occurrence of the equinoxes each year due to the slow continuous westward shift of the equinoctial points along the ecliptic by 50 seconds of arc per year. It is caused by the precession of the earth's axis around the ecliptic pole, with a period of 25 800 years

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Etymology

Origin of precession of the equinoxes

First recorded in 1615–25

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Example Sentences

See Examples For:

precession of the equinoxes

But modern astrologers have forgotten about the precession of the equinoxes, which Ptolemy understood.

From "Cosmos" by Carl Sagan

You must remember that there has been a precession of the equinoxes since the time of Atlantis, with a consequent shift in the earth's axis.

From Astounding Stories of Super-Science, May, 1930 by Harry Bates

The final theory for accounting for the ice age is attributed to what is termed the precession of the equinoxes.

From Nature's Miracles, Volume 1 Familiar Talks on Science—World-Building and Life. Earth, Air and Water. by Elisha Gray

The earth's equatorial protuberance, being acted on by the attraction of the sun and moon, must disturb its axis of rotation in a calculated manner; and thus is produced the precession of the equinoxes.

From Pioneers of Science by Sir Oliver Lodge

Indeed, his great discovery of the precession of the equinoxes was essentially founded on the discussion of the Alexandrian observations on Spica Virginis made by Timochares.

From History of the Intellectual Development of Europe, Volume I (of 2) Revised Edition by John William Draper

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