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Does the Sun’s Rotational Axis Precess?

-- | June 26, 2015

Question: The earth has the north celestial pole position today near Polaris and has a 25000 year cycle circle. What is the same for the SUN’s north celestial pole and wobble? — David

Answer: The precession of the Earth’s rotational axis comes about due to tidal torques caused mostly by the differential pull on the Earth by the Moon and the Sun. These tidal torques cause the Earth to become less than spherical (oblate). The Sun, on the other hand, is very nearly spherical, and its rotation axis is very nearly aligned with that of Jupiter’s (tilt with respect to Jupiter is about 6 degrees). The Sun also has a relatively small rotation rate of about one revolution every 25.5 days. All of these factors conspire to produce a very small precession rate for the rotation axis of the Sun.

Jeff Mangum

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