Author Question: Both RR Lyrae and Cepheid variable stars are stars that, when on the main sequence, were considered ... (Read 94 times)

cnetterville · **on:** Jul 27, 2018

Both RR Lyrae and Cepheid variable stars are stars that, when on the main sequence, were considered to be:

A) low mass.
B) intermediate mass.
C) high mass.
D) zero-age main sequence.
E) blue stragglers.

Question 2

The period from about 100 seconds up to 15 minutes after the Big Bang is the:

A) Radiation Era.
B) Lepton Epoch.
C) Nuclear Epoch.
D) Decoupling Epoch.
E) Matter Era.