The Solar Analemma over Edmonton

The Solar Analemma over Edmonton June 21, 2013 - June 2, 2014 If observed at the same time each day, in the course of a year, the Sun’s position in the sky traces a figure-8 shaped curve called the “analemma“. The analemma is produced by the combined effects of the Earth’s tilted axis of rotation and its variation in speed along its elliptical orbit around the Sun. Over the year, the Earth’s axial tilt shifts the Sun’s position north/south and the Earth’s elliptical orbit shifts it east/west. Solstices correspond to the top and bottom of the figure-8, indicating the northern and southernmost limits of the Sun in the sky. The cross-over point on the curve is around both April 12 and August 30 as the Sun’s apparent position ascends and descends respectively. The analemma curve is also a graphical representation of the equation of time which describes the difference between sundial time (apparent solar time) and clock time (mean solar time). My project to image the solar analemma with a digital camera had two objectives: (1) capture the figure-8 curve of the Sun’s position over a year above an Edmonton foreground in a single composite image, and (2) capture the changes of the four seasons in Edmonton in a timelapse movie with the figure-8 evolving as the seasons progressed. This is the timelapse movie illustrating the Sun’s motion on the analemma curve, from June 21, 2013 to June 2, 2014. Each solar image was taken at 9:45 AM at St. George’s Crescent in Edmonton, Alberta, Canada. The foreground images showing the changes of the four seasons were taken at the same location, some at 09:45 AM and others in the afternoon. The movie is best viewed in full-screen HD with sound. The composite image can be viewed at: @N05/15084201381/