Multiple Choice
Cepheid and RR Lyrae variable stars change their brightness by ____.
A) atmospheric explosions of hydrogen gas
B) internal changes in their fusion processes
C) a combination of atmospheric explosions and internal changes
D) a combination of atmospheric explosions and physically pulsating
E) changing its period between pulses
Correct Answer:

Verified
Correct Answer:
Verified
Q16: As a one-solar-mass star evolves off the
Q17: Cepheid variable stars are classified as either
Q18: The age of a star cluster can
Q19: Why is there an upper end in
Q20: There is a mass-luminosity relationship because stars
Q22: Variables of a certain type are called
Q23: Explain how the age of a star
Q24: Why do Cepheids pulsate?
Q25: The energy emitted from the surface of
Q26: Stellar models can easily be accomplished by