1. Helium Ignition a. On the HR Diagram, show the general process of a main sequence star like the Sun leaving the main sequence. b. Describe how the size of the overall star (total radius) changes during this phase, and relate that to what is happening in the star's core. 1007 ~ 10 = . ' = 10 N = Thel w el i = 1 10-= 40,000 20,000 10,000 5,000 2,500 Temperature (K)