An H-R diagram for a globular cluster will show a horizontal branch—a 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.
Answer:C
An H-R diagram for a globular cluster will show a horizontal branch—a 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.