Star Clusters

Which sentence from paragraph 2 supports the idea that star clusters are held together by gravity?

• "A star cluster is a group of stars in a small area"

• "As a star cluster moves, its stars move as a group"

• "Open clusters can be about 50 light-years across"

• "The two types of clusters do not have a lot in common"

What is the meaning of the word astronomer as it is used in the passage?

• a designer and make of telescopes

• an astronaut who travels to distant solar systems

• a writer who creates descriptive names for stars and planets

• a scientist who studies stars and other objects in space

What is the relationship between stars in a cluster?

• The weight of each star makes the stars in the group smaller.

• Each star helps make the other stars become hotter.

• The size of each star makes the group seem closer to Earth.

• Each star influences how other stars in the group move.

How does the author support the idea that open clusters are very different from globular clusters?

• He cites quotations from expert scientists.

• He gives the reader a photograph to examine.

• He provides information about both formations.

• He relates evidence that he has seen personally.

Select three sentences that support the claim in question 4?

• "Based on our experiences of the Sun, it's easy to think all stars are field stars."

• "Astronomers talk about two types of clusters: globular and open."

• "The two types of clusters do not have a lot in common."

• "They have hundreds or thousands of stars, not millions."

• "Only the most powerful telescopes can get a good look at one of them."

Which detail about globular clusters does the photograph on page 1 make clear?

• Globular clusters are billions of years old.

• Globular clusters contain billions of stars.

• Globular clusters are spherical in shape.

• Globular clusters contain red giants.