Author: Iryna Butsky Co-Author: Juliette Becker
- We know that the angular diameter of the sun d = 0.5 degrees. We also know that the size of the semi-major axis of the Earth's orbit around the sun, a = 1.5 x 10^13cm.
- We can now set up a simple proportion to find the radius of the sun. From this, we find that the radius of the sun is about 6.5 * 10^10 cm.
- Therefore, the AU, in solar diameters is
- From Newton's version of Kepler's third law we have the following equation we know that P =31,556,926 secons , a = 1.5*10^13cm, and G = 6.674*10^-8 cm^3 g^-1s^-2. Plugging the numbers in we find that the mass of the Sun is about 2*10^33g.