Correct definition of planetary precession

In summary: This phenomenon is known as the precession of the equinoxes. Although there may be slight variations in the measurements and terminology among different sources, the general definition and understanding of planetary precession remains the same.
  • #1
jamadagni
7
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Hello. Can anyone please provide me with an authoritative definition of planetary precession? Any link to an authoritative source would be best. I did do my googling first. I tried to provide my search results but an ostensibly spam-blocking feature does not allow me to post the links because I have not made 15 posts on these forums yet. Stupid in that it does not allow even legitimate results.

The Wolfram Labs page on this mentions merely the change of the orientation of the ecliptic plane in space.

Wikipedia mentions two things: the 47" /cy shift of the ecliptic plane (same as above) and something else "whose center lies on a circle about 6° away from the poles".

Another website gives a shift of 0.13" /yr caused by the movement of the ecliptic.

One website says "the planetary precession (which makes not the ecliptic pole the centre, but a circle about 6° away from it)".

So which is the correct definition? I know that the ecliptic rotates around an axis at the rate of 47" /cy, and that this causes a change in the ecliptic longitude of bodies, but is this the 0.13" /yr mentioned in one site? And what is this "6° away from the poles" point?

Thanks in advance.
 
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  • #2
The authoritative definition of planetary precession is the slow, continuous change in the orientation of the ecliptic plane in space. This shift is due to the gravitational forces generated by the other bodies in the solar system, and results in a slow change in the position of the celestial poles, as well as a slow change in the direction of the Earth's axis of rotation. The rate of this precession is 47”/cy, or 0.13”/yr. In addition, this precession causes the Earth's equinoxes to rotate in a circle around the celestial poles, with a center that lies on a circle about 6° away from the poles.
 

What is planetary precession?

Planetary precession refers to the gradual shift in the orientation of a planet's rotational axis over time. This phenomenon is caused by the combined gravitational forces of the Sun, Moon, and other planets acting on the planet's equatorial bulge.

What causes planetary precession?

Planetary precession is primarily caused by the gravitational pull of the Sun and the Moon on a planet's equatorial bulge. Additionally, the gravitational forces of other planets in the solar system can also contribute to precession.

How does planetary precession affect our planet?

Planetary precession has several effects on our planet, including changing the length of a day and the position of the stars in the sky over thousands of years. It also affects the Earth's climate by altering the distribution of sunlight and the location of the polar ice caps.

How is planetary precession measured?

Planetary precession is measured using a variety of astronomical techniques, such as astrometry, which tracks the position of stars over time, and satellite data, which measures changes in the Earth's gravitational field caused by precession.

Why is planetary precession important to study?

Understanding planetary precession is important for accurately predicting astronomical events and climate changes on Earth. It also provides insight into the dynamics of our solar system and the interactions between celestial bodies.

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