Pole Star - Effects of Axial Precession

Effects of Axial Precession

Although the south Celestial pole currently lacks a bright star like Polaris to mark its position, slow changes over time (due to the effects of precession) mean that other stars will become southern pole stars.

The Celestial south pole is moving toward the Southern Cross, which has pointed to the south pole for the last 2,000 years or so. As a consequence, the constellation is no longer visible from subtropical northern latitudes, as it was in the time of the ancient Greeks.

There have been many pole stars throughout the millennia. Around 2000 BC, the star Eta Hydri was the nearest bright star to the Celestial south pole. Around 2800 BC, Achernar was only 8 degrees from the south pole.

In the next 7500 years, the south Celestial pole will pass close to the stars Gamma Chamaeleontis (4200 AD), I Carinae, Omega Carinae (5800 AD), Upsilon Carinae, Iota Carinae (Aspidiske, 8100 AD) and Delta Velorum (9200 AD). From the eightieth to the ninetieth centuries, the south Celestial pole will travel through the False Cross. Around 14000 AD when Vega is only 4 degrees from the North Pole, Canopus is only 8 degrees from the South Pole and is, thus circumpolar on the latitude of Bali (8 deg S).