Measurement of the Sun’s Diameter using the Pinhole

SPU-21 Fall 2015

The physical diameter of a star is fundamental for its temperature, luminosity (energy output), and other important properties. It is easy to determine the diameter of the Sun if we know its distance, the Astronomical Unit (AU), which is approximately 1AU = 1.5x 108 km. The method we will use to measure the angular diameter of the Sun is simple geometry.

What you'll need: