Editing Sigma Octantis (section)

==Southern pole star==
Sigma Octantis is the current southern [[pole star]], whose counterpart is [[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 slightly more than a degree away from the true south pole, and the south celestial pole is moving away from it due to [[Axial precession|precession of the equinoxes]].

[[File:Octans trapezoid.GIF|thumb|left|The south celestial pole. The trapezoidal asterism at the centre includes Sigma Octantis.]]

At magnitude&nbsp;+5.42, Sigma Octantis is barely visible to the naked eye, making it unusable for navigation, especially by comparison with the much brighter and more easily visible [[Polaris]].<ref name=Jumk/>
Because of this, the [[constellation]] [[Crux]] is often preferred for determining the position of the [[Celestial pole|South Celestial Pole]].<ref name=CSIRO/>
Once Sigma Octantis' approximate position has been determined, either by the major stars in [[Octans]] or using the Southern Cross (Crux) method, it can be positively verified using an [[Asterism (astronomy)|asterism]]: Sigma, [[Chi Octantis|Chi]], [[Tau Octantis|Tau]], and [[Upsilon Octantis]] are all stars of around magnitude&nbsp;5.6, and form the distinctive shape of a [[trapezoid]].