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.

---

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

---

Etymology

Origin of precession of the equinoxes

First recorded in 1615–25

Example Sentences

The conjunction of the sun with Sirius alters somewhat with differences in latitude and the precession of the equinoxes.

From Washington Times

The pair fall into a conversation about the precession of the equinoxes: this, apparently, is how planetary scientists catch up.

From Scientific American

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

From Literature

He only hit the jackpot when he took into account the orbit around the Sun, and the long variations caused by the precession of the equinoxes.

From Nature

The al-Aalam mentioned above was also an able astronomer, and in addition to numerous observations made at Baghdad, he determined with great care the precession of the equinoxes.

From Project Gutenberg