Have a look at the sky : it seems the celestial objects are moving about a central point, called celestial pole.

The Southern Cross apparently turning about the Southern Celestial Pole

12th Feb. 2016, Reunion Island (Lat. -20.899645, Long 55.545388) on 2016 Feb. 12, circa17:00 GMT

There are two kinds of star rotation : the apparent rotation and the real rotation. The real star rotation is imperceptible from the Earth because we are very far away from them.

But the apparent rotation gives us the impression that the stars are turning about the axe that joins the North Celestial Pole and the South Celestial Pole.

 

 

 

La Reunion is an Earth point where it's interesting to watch the apparent motion of the sky because you can detect the Celestial South Pole.

In the Northern Hemisphere, the Celestial North Pole can be localised with the North Polar Star but in the Southen Hemisphere, no star corresponds to the South Celestial Pole.

HOW TO FIND IT?

Some tricks is detailed below:

 

 

 

As you can see, it's very easy ... but the drawback is that the Crux only gives us an approximation of the position of the Celestial South Pole.

 

 There is a second way to find the Celestial South Pole !

 

In your mind, when you have found the Crux, make a line with the biggest side of this constellation [Acrux and Gacrux].

 

Then, find the two stars alpha and beta of constellation of Centaurus and draw by the segment [alpha beta], the perpendicular bisector which intercept the line [Acrux-Gacrux].

 

The intercept-point of the two right is the Celestial South Pole !