List the Two Basic Types of Intrinsic Variable Stars

Q10: Briefly explain why there is a main

Q11: Astronomers determine the internal structure of a

Q12: When a gas is so dense that

Q13: The period-luminosity relation for Cepheid and RR

Q14: Observing star clusters will give astronomers needed

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