An H-R diagram for a globular cluster will show a horizontal ...

[luminitza]

An H-R diagram for a globular cluster will show a horizontal brancha line of stars above the main-sequence but to the left of the subgiants and red giants. Which of the following statements about these horizontal branch stars is true?
 
  A) They have inert (non-burning) carbon cores.
  B) Their sole source of energy is hydrogen shell burning.
  C) They generate energy through both hydrogen fusion and helium fusion.
  D) In a particular star cluster, all horizontal branch stars have the same spectral type.

Question 2

The age of a star cluster may be estimated by determining the ________ of the Main Sequence at which stars are just in the process of evolving away to become giant stars.
 
  Fill in the blank(s) with correct word

[elizabethrperez]

Answer to Question 1

C

Answer to Question 2

turn-off point

[luminitza]

Excellent

[vickybb89]

Gracias!