Octans, the Octant, is the faint constellation that holds the south celestial pole, the point around which the whole southern sky turns each night.
At a glance
| stars in the figure | 3 |
|---|---|
| nearest star of the figure | Nu Octantis, 69.1 light-years (21.2 pc) |
| farthest star of the figure | Delta Octantis, 299 light-years (91.7 pc) |
| depth | the farthest is 4.3 × farther than the nearest |
Read off the piece’s own catalogue, the same values it draws with.
About Octans
Octans was named by Nicolas-Louis de Lacaille after the octant, the reflecting instrument navigators used to measure the height of the Sun and stars above the horizon. It is a sprawling, dim region with no bright star, and its most important feature is a point with nothing in it: the south celestial pole, where Earth’s axis points into the southern sky.
The north has Polaris, a bright star close to its pole. The south has no such luck. The nearest naked-eye star to the southern pole, Sigma Octantis, is so faint that it is hard to see without a dark sky, and southern observers usually find the pole by sighting along the Southern Cross instead.
Octans never sets from anywhere in the southern hemisphere and never rises anywhere in the northern hemisphere: it is always above the southern horizon and always below the northern one.
What you see in the piece
Its figure is three faint stars. Turn on CONSTELLATIONS (N) and leave the HUMAN EYE view (E): the nearest lies a few times closer than the farthest, and the triangle around the pole stretches out in depth as you fly.
Questions
Is there a south pole star?
There is no bright southern pole star. The closest naked-eye star to the south celestial pole is Sigma Octantis, in Octans, and it is only just visible under a dark sky.
How far away are the stars of Octans?
The nearest star of the figure is Nu Octantis, 69.1 light-years (21.2 pc); the farthest is Delta Octantis, 299 light-years (91.7 pc). The farthest is 4.3 × farther than the nearest.