If I knew the mass of the Sun and the gravitational constant (G), I could easily find the distance to the sun using the angular velocity of the Earth. I will just chalk this up as a big mistake.

However, if you know the angular size and distance the size can be calculated. But what is this angular size for the whole image? Using the Sun There are two useful things about the Sun.

Here we present a distance to the Cepheid ζ Geminorum, determined using a direct measurement (by an optical interferometer) of its changes in diameter as it pulsates.