2-11-11
Introduction to the Hertzsprung-Russell diagram and a chance to see the diagram in “action” via the HR Diagram Explorer as seen on the left. Students worked on questions (pdf) with the website. Note that the temperature increases as one moves to the LEFT and that luminosity increases as one moves towards the TOP of the diagram. The green “path” represents the Main Sequence. Our Sun would plot at a surface temperature of 5800K and a luminosity of 1 (10^0). Note the color and size of the star on the left and the equation that uses the luminosity and temperature to determine the radius of the star.