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Review Quiz No. 17

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1. The radius in the interior of a star where fusion processes can no longer take place.

2. The point in time of a star’s life when nuclear fusion of hydrogen into helium ceases.

3. The point in time of a star’s life when nuclear fusion processes cease alltogether.

4. The point in a rotating star cluster beyond which a star is no longer gravitationally bound to the cluster.

5. The point on the main sequence of a star cluster above which stars have evolved to red giants.

Question 1: What is the “Turn-

Off Point”?

Question 2:Comparing the Hertzsprung-Russell diagrams of 2 star clusters, A and B,

you find that the turn-off point of cluster A occurs in the range of F stars, while that of cluster B occurs in the range of K stars. From this, you can infer that …

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1. A is closer to us than B.

2. B is closer to us than A.

3. A is older than B.

4. B is older than A.

5. A contains more stars than B.

Question 3:The longer a Cepheid variable’s oscillation

period, …

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1. the brighter (more luminous) it is.

2. the fainter (more luminous) it is.

3. the longer its rotation period is.

4. the shorter its rotation period is.

5. the younger it is.

Question 4:Cepheid variables can be

used for distance measurements …

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1. only within the solar system.

2. only in the immediate solar neighborhood

3. only within our Milky Way.

4. to neighboring galaxies.

5. throughout the entire visible Universe.