The Moving Stars of the Northern Hemisphere

I present a short time-lapse video montage showing the motion of the northern hemisphere sky, to complement a similar montage here on YouTube of the southern hemisphere sky. Both sets of time-lapses were shot from about 32° latitude, north and south. The video shows four views looking in each direction, demonstrating how the sky moves through the night. Stars set in the west and rise in the east, and turn in circles counter-clockwise when looking to the north, to the celestial pole. The montage ends looking to the south, in a time-lapse sequence taken from dusk to dawn. Note the Zodiacal Light in the west (right) at the start of the night and in the east (left) at the end of the night. Also note the bands of red and green airglow moving across the sky in some sequences. For those who wonder why I used a fish-eye lens, it was for a very good reason. Though a rectilinear lens would have provided a flat horizon, it would have also distorted the star tails into elongated ellipses due to the inherent distortion of such lenses. The fish-eye preserves a more natural appearance to the sky and its motion. I shot the time-lapse sequences over four nights in December 2015, at the Quailway Cottage, near Portal, Arizona and the Arizona Sky Village. I used a Canon 6D and Canon 15mm full-frame fish-eye lens at f/2.8, taking about 450 frames for each of the east, west, and north sequences, and 900 frames for the all-night south sequence, each frame being a 45 second exposure at ISO 3200. I processed the images with Adobe Camera Raw and LRTimelapse, and created the frames for the star trail movies and stacked still images using the Advanced Stacker Plus actions from . Music is by Adi Goldstein /