Luminosity (solar units) 10,000 1,000 100 10 1 - .01 .001 .0001 ● S . T 20,000 10,000 W Temperature (K) 5,000 X Y 6. Star S has a greater surface temperature than Star X. Given that Star X is just as luminous as Star S, what can you say about the size of Star X compared to Star S? Explain your answer. 7. Based on the H-R diagram, which star is larger, X or Y? How do you know? 8. Based on the H-R diagram, which star is smaller, Y or T? How do you know? 9. It is very difficult to predict how the size of Star S will compare to that of Star W (without doing a calculation). Explain why comparing the size of these stars is so difficult?

Luminosity (solar units) 10,000 1,000 100 10 1 - .01 .001 .0001 ● S . T 20,000 10,000 W Temperature (K) 5,000 X Y 6. Star S has a greater surface temperature than Star X. Given that Star X is just as luminous as Star S, what can you say about the size of Star X compared to Star S? Explain your answer. 7. Based on the H-R diagram, which star is larger, X or Y? How do you know? 8. Based on the H-R diagram, which star is smaller, Y or T? How do you know? 9. It is very difficult to predict how the size of Star S will compare to that of Star W (without doing a calculation). Explain why comparing the size of these stars is so difficult?