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Star Trails!

In June 2015 we took a set of time lapse photos while pointing our camera to Polaris which is the Northern Star.  Polaris is almost at the Celestial North Pole.  If you point straight up from the axis of the Earth’s rotation, you will be pointing toward the Celestial North Pole.  Here is a diagram that shows this:

So, when you point the camera to Polaris and leave the shutter open for a few minutes, it appears to stay in the same place.  In fact, Polaris is up all night and day!  But the sun shines so bright that you can’t see it.  And stars around it seem to move in a circle (actually it is US on Earth that are moving).  The further away from Polaris, the faster the stars seem to move.  In the photo below, I took five exposures of three minutes each.  I have software then, that effectively adds each image together and get this photo.  Note that the brightest star in the center is Polaris.  It is so bright because it is relatively stationary so it brightens as you add all the images together.