A few nights ago I set up my tripod and camera in our unused back staircase. I remembered that the staircase had a small north-facing window that had a mostly unobstructed view of the sky. I set the camera to take consecutive 25-second exposures. I had forgotten to change out the batteries that I had used extensively a few days earlier; thus, the camera ran out of power around 3:00am. The photo above is a composite of over 1,200 photos taken over seven hours. The stars rotated around the bright North Star in the middle of the circles. The North Star stands roughly over the North Pole axis of the earth. All the other stars appear to circle around the North Star, but in reality the earth spins and causes this visual effect.