The following questions refer to the H-R diagram below that shows the life track of a 1-solar-mass star,with various stages labeled with Roman numerals.

-During which stage does the star have an inert (nonburning)helium core?
A)iii
B)iv
C)vi
D)vii
E)viii

Question

The following questions refer to the H-R diagram below that shows the life track of a 1-solar-mass star,with various stages labeled with Roman numerals.
 
-During which stage does the star have an inert (nonburning)helium core?
A)iii 
B)iv 
C)vi 
D)vii 
E)viii

Quizplus · Accepted Answer

Stage iv, also known as the subgiant branch, is where the inert helium core forms. This occurs after hydrogen burning in the core has ended and the core begins to contract and heat up, causing hydrogen burning to occur in a shell surrounding the core. However, the core is not yet hot enough to ignite helium burning, making it inert.

The Following Questions Refer to the H-R Diagram Below That