What is approximate numerical equation of the apsidal precession of the Earth-Moon barycenter? Or is it only constant 11.45 arcsec/year with unchanged accuracy to 0.01 arcsec/year for a million years? And changes of the planets orbits do not influence on the apsidal precession of the Earth-Moon barycenter at time interval of a few millions years?

For example planets create significant influence on precession of Earth and the ecliptic at time interval of a few thousands years. Therefore precession of Earth and the ecliptic are not constant. There are numerical equations for precession of Earth and the ecliptic.

  • $\begingroup$ I think The constant $11.45 arcsec/year$ is The Perhelion shift of the Earth i.e apsis between the earth and the Sun not the earth-moon barycenter $\endgroup$
    – user47732
    Jan 4 at 15:36
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    $\begingroup$ @ScienceAJ Imyaf isn't talking about the apsidal precession of the Earth and Moon about the EMB, they're asking about the precession of the EMB's solar orbit. $\endgroup$
    – PM 2Ring
    Jan 4 at 23:21
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    $\begingroup$ @ScienceAJ The Earth's orbit around the Sun is only approximately a Keplerian ellipse. A better approximation considers the EMB (Earth-Moon barycentre) as the entity orbiting the Sun. Of course, that isn't a perfect Kepler orbit either, but we can approximate it quite well as an ellipse which slowly varies. I have some info related to the EMB aphelion here: astronomy.stackexchange.com/a/49605/16685 $\endgroup$
    – PM 2Ring
    Jan 4 at 23:30
  • $\begingroup$ Thanks @PM2Ring. $\endgroup$
    – user47732
    Jan 5 at 4:11
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    $\begingroup$ @Imyaf The Horizons data for the Sun and the EMB spans 20,000 years. See ssd.jpl.nasa.gov/horizons/time_spans.html JPL have data beyond that range, but it's not accessible through Horizons. The Horizons system only provides numerical data. If you want graphs you have to make them yourself, eg by writing code or using a spreadsheet. $\endgroup$
    – PM 2Ring
    Jan 5 at 8:25


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