Stars around the ClockStars draw trails around a sundial. | ||||||||||||||||
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Stars circle around the north celestial pole in this two hour long exposure. The equatorial sundial in Swabian Jura,
Southern Germany, shows the relation to the earth. The gnomon of the sundial points (more or less) to the north celestial pole,
i.e. gnomon and rotation axis of the earth are parallel. The equatorial ring of the sundial fits to the circles of the stars.
Therefore this kind of sundial equals the earth with its rotation axis, equator, and the great circle of the meridian.
In sunlight the gnomon casts a shadow onto the ring of the equator with its hourly tick marks. On top of the gnomon is
an iron star resembling the direction to Polaris, the north star. Polaris ís the bright star with the very short star trail,
i.e. it is very close to the north celestial pole (all around the clock) and therefore showing the north direction.
527 exposures of 13 s were combined for this view. A couple of planes and satellites are crossing the field,
whereas the brightest planes were removed from the original frames. The red light is from preparing a second
camera into the opposite direction: |
