“South Star” over Namibia

Via APOD, a beautiful demonstration of the Earth’s rotation:

startrails11h_hambsch_c90.jpg

(image: Josch Hambsch)

This is an 11-hour exposure composite image of star trails over the skies of Namibia.

The trails make semicircles due to the Earth’s rotation about its axis over the 11 hours (about half a day) of the exposure. If you extended the South Pole out into space (the “celestial pole”), it would be the center of the concentric circles shown. So the center of the star trails pictured is not the “North Star” Polaris, but rather the South celestial pole.

Here‘s a similar image from the Northern hemisphere, centered on the North Star.

There is also a “South Star” (sort of), but in part because it never mattered much in navigation or (Western?) culture, it was never called such colloquially.

Poor little South Star.

http://antwrp.gsfc.nasa.gov/apod/ap060915.html

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