Based on what you learned about stellar evolution, select all of the correct statements from the following list. 1. The period of some Cepheid variables actually changes. 2. When getting dimmer, variable stars are releasing energy; when getting brighter they are storing energy. 3. variable stars are expanding and contracting 4. despite their variability, variable stars stay in a specific position on the H-R diagram. 5. A changing period in a Cepheid variable means that the size of the star is changing and that the star is therefore evolving. 6. Only stars on the instability strip are variable. 7. More massive stars will vary their brightness more quickly.

Based on what you learned about stellar evolution, select all of the correct statements from the following list. 1. The period of some Cepheid variables actually changes. 2. When getting dimmer, variable stars are releasing energy; when getting brighter they are storing energy. 3. variable stars are expanding and contracting 4. despite their variability, variable stars stay in a specific position on the H-R diagram. 5. A changing period in a Cepheid variable means that the size of the star is changing and that the star is therefore evolving. 6. Only stars on the instability strip are variable. 7. More massive stars will vary their brightness more quickly.