Chapter 9, Problem 13SEQ

Explain all answers clearly, with complete sentences and proper essay structure if needed. An asterisk(*) designates a quantitative problem, for which you should show all your work.

Homes to Civilization? We do not yet know how many stars have Earth like planets, nor do we know the likelihood that such planets harbor advanced civilizations like our own. However, some stars can probably be ruled out as candidates for advanced civilizations. For example, given that it look a few billion years for humans to evolve on Earth, it seems unlikely that advanced life would have had time to evolve around a star that is only a few million years old. For each of the following stars, decide whether you think it is possible that it could harbor an advanced civilization. Explain your reasoning in one or two paragraphs.

a. A $10M_{Sun}$ main -sequence star

b. A $1.5M_{Sun}$ main-sequence star

C. A $1.5M_{Sun}$ red giant

d. A $1M_{Sun}$ helium-fusing star

e. A red supergiant