Great Year

[Eagle]

I have a question for the community of Wave59.

Can we agree the exact amount of time to complete the Great Year. The web likes to show different lengths of time which range from 25,800 years to the more favourable 25,920 years.

Thank you

[sbank]

FWIW, this is what ChatGPTs answer was. (Doesn't really help you, but I guess it shows why there is no one correct answer.)

The term "Great Year" typically refers to a concept related to astronomy and astrology, representing the time taken for the sun to complete a full cycle through the twelve constellations of the zodiac. This cycle is also known as the precession of the equinoxes.

The exact duration of a Great Year is approximately 25,772 years. This value is derived from the Earth's slow axial precession, which causes the orientation of Earth's axis to slowly change over time. This gradual wobble results in the shifting of the position of the stars relative to Earth's axis and the changing of the pole star.

This cycle is an astronomical phenomenon and isn't universally agreed upon as a precise length of time due to variations in calculations, but the commonly accepted figure is around 25,772 years. This value is an estimate based on astronomical observations and mathematical calculations.

So I almost think this needs to be calculated with an exact ephemeris that takes into account the earth wobble.

[Eagle]

It’s an interesting discussion because the time length of the Great Year will have an impact on all the divisions of that length.

If it takes the Sun 25,920 years to complete a full cycle through the twelve constellations of the zodiac, then we have nice rounded numbers for our divisions. However, if it takes 25,772 years to complete a full cycle then our divisions change.