- South Star
A modern invention, the term South Star, also called southern
pole star , refers to thestar that happens to lie closest to the southcelestial pole (SCP), and which appears (approximately) directly overhead to an observer at the Earth'sSouth Pole . At present, thenaked-eye star nearest to this imaginary point isSigma Octantis , whoseangular separation from the pole is about 1° (as of2000 ). Itsapparent magnitude is a very faint 5.45, and as such it is not very useful for generalnavigation al purposes. This is in contrast to the much brighter 2nd magnitudeNorth Star ,Polaris , which marks the approximate position of the north celestial pole.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. For example, in the next 7500 years, the south celestial pole will pass close to the stars GammaChamaeleon tis (4200 CE),I Carinae , Omega Carinae (5800 CE), Upsilon Carinae, Iota Carinae (Aspidiske , 8100 CE) and Delta Velorum (9200 CE).A similar concept applies to other planets; see
Pole Star for details.ee also
*
Pole star
*Circumpolar star
*North star
*Celestial sphere
*Celestial pole
*Celestial equator
*Apparent magnitude
*Angular separation
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