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

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 Bates, Harry

The Mesopotamian of to-day is surely not the superior of his sculptured ancestors who observed and measured the precession of the equinoxes nearly 6,000 years ago.

From The Color Line A Brief in Behalf of the Unborn by Smith, William Benjamin

But owing to the precession of the equinoxes, this point has now moved back into Pisces.

From Astronomical Curiosities Facts and Fallacies by Gore, J. Ellard

This enabled him to ascertain the motion of the equinoxial points, and his value of the constant of precession of the equinoxes is exceedingly accurate for a first determination.

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