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

Example Sentences

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

From "Cosmos" by Carl Sagan

Hipparchus had, by most sagacious interpretation of certain observations of his, discovered a remarkable phenomenon called the precession of the equinoxes.

From Pioneers of Science by Lodge, Oliver, Sir

Even the tides and precession of the equinoxes and Bradley's nutation were accounted for and explained.

From Astronomy: The Science of the Heavenly Bodies by Todd, David Peck

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 Bates, Harry

Mahometan and Chinese know what we know of leap-year, of the Gregorian calendar, and of the precession of the equinoxes.

From The Voice of Science in Nineteenth-Century Literature Representative Prose and Verse by Various