|T. Credner & S. Kohle
© Copyright by the observers
Long exposed images of the starry sky show star trails if they are not guided to earths rotation. Picturing the northern sky on such photographs gives nice circles around the celestial pole, where earth's axis points to. However, the southern hemisphere stars apparently rotate around the southern celestial pole. This also shows up in the above photo of the celestial equator. Stars on the equator leave straight lines on the image. North of the equator star trails are curved upwards and southern star trails downwards.