北天极

这样，晷针的上端正好指向北天极，下端正好指向南天极。

The upper end of the sundial points right to the North Pole ， and the lower end to the South .

整个铜球可以绕一根金属轴转动，转动一周代表一个昼夜。球面与金属轴相交于两点：北天极和南天极。

The sphere is mounted by its poles ( corresponding to the celestial poles ) on a metal axis ， and can rotate around it .

这张数码合成照片的中心位置是北天极，作为天空中所有星迹圆弧的中心点，北天极很容易找到。

Towards the middle of the above digitally stretched picture is the North Celestial Pole ( NCP ), easily identified as the point in the sky at the center of all the star trail arcs .

居住在北半球的人永远看不到接近南天极的星，而居住在南半球的人同样也看不到接近北天极的星。

People in the northern hemisphere can never see stars near the south celestial pole , and people on the southern hemisphere can never see polaris .