The Changing Declination of the Sun in the Sky


SPU-21 Fall 2015

This lab will measure the daily change in elevation above the horizon if it were measured at exactly noon. Combined with the latitude of Cambridge, this give us the solar Declination, or celestial latitude, which changes with the season with a max/min of ~ +/- 23.5 degrees on the Solstices. If we measure the rate of change (degrees per day) we can attempt to predict the solar Declination on the Winter (or Summer) solstice, which is also the same number as the tilt of the Earth's axis of rotation with respect to the plane of the Earth's orbit around the sun. This angle is the Obliquity of the Ecliptic.