Sigma Octantis

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{{Starbox begin | name=Sigma Octantis }} {{Starbox image | image=Image:Octans 01.gif | caption=Octans and around, with Sigma Octantis in the middle marked in cyan. }} {{Starbox observe | epoch=J2000 | ra=21^h 08^m 46.8^s | dec=-88° 57′ 23″ | appmag_v=5.42 | constell=Octans }} {{Starbox character | class=F0 III | b-v=0.27 | u-b=0.13 | variable=Delta Scuti }} {{Starbox astrometry | radial_v=+11.9 | prop_mo_ra=25.96 | prop_mo_dec=5.02 | parallax=12.07 | p_error=0.48 | dist_ly=270 | dist_pc=83 | absmag_v=0.83 }} {{Starbox catalog | names=Polaris Australis, HR 7228, HD 177482, SAO 258857, FK5 923, HIP 104382. }} Template:Starbox end Sigma Octantis (σ Oct / σ Octantis) is a magnitude 5.5 star in the constellation Octans.

Its position near the southern celestial pole makes it the southern hemisphere's pole star and counterpart to Polaris, the current North Star. To an observer in the southern hemisphere, Sigma Octantis appears almost motionless and all the other stars in the Southern sky appear to rotate around it. It is part of a small "half hexagon" shape. It is over a degree away from the true south pole, and the south pole is moving away from it due to precession of the equinoxes.

Sigma Octantis is sometimes called Polaris Australis, or South Star. However, it is a faint star—at magnitude 5.5 it is barely visible to the naked eye—which makes it a rather poor pole star, especially by comparison with the much brighter and easily visible Polaris.

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