G goerge f Guest Jan 9, 2009 #3 The mass, age, and composition of the star. Heavier elements fusing usually give more energy.
B Brun the Leader Guest Jan 9, 2009 #5 Nuclear reaction rate, opacity, method of energy transport in the core, and the rate of gravitational contraction (if the star is variable or past TAMS).
Nuclear reaction rate, opacity, method of energy transport in the core, and the rate of gravitational contraction (if the star is variable or past TAMS).