Question 1

Star clusters provide a way to test stellar evolution theory because&#10;A) all the stars in a cluster are the same age and the same type.&#10;B) all the stars in a cluster are different ages and come in many different types.&#10;C) all the stars in a cluster are the same age and come in many different types.&#10;D) all the stars in a cluster are different ages and the same type.

Accepted Answer

Star clusters, particularly open and globular clusters, are excellent laboratories for testing theories of stellar evolution because all the stars within a cluster formed roughly at the same time from the same molecular cloud. This means they are approximately the same age but can vary widely in mass, leading to a diversity in their evolutionary stages and types at any given time. This variation allows astronomers to observe and compare different stages of stellar evolution within the same cluster.

Question 2

When looking at stars, the brightest are the easiest to study. This is called&#10;A) bright effect.&#10;B) selection effect.&#10;C) mass effect.&#10;D) radius effect.

Accepted Answer

The term "selection effect" refers to the bias introduced into a study or observation due to the criteria used for selecting objects or data to be examined. In the context of studying stars, the brightest stars are more likely to be studied because they are easier to observe, leading to a selection effect where the sample of studied stars may not be representative of all stars.

Question 3

This type of cluster has upwards of 1 million stars:&#10;A) closed cluster&#10;B) globular cluster&#10;C) open cluster&#10;D) stellar association

Accepted Answer

Globular clusters are large groups of old stars that can contain hundreds of thousands to millions of stars, densely packed into a spherical shape.

Question 4

A group of stars that is few hundred light years across and contains about 100 stars is likely a ______.&#10;A) closed cluster&#10;B) globular cluster&#10;C) open cluster&#10;D) stellar association

Accepted Answer

The answer of A group of stars that is few...

Question 5

A cluster of a few hundred thousand stars is likely a _______.

Accepted Answer

The answer of A cluster of a few hundred thousand...

Question 6

The point where a star leaves the main sequence is called its ________.

Accepted Answer

The answer of The point where a star leaves the...

Question 7

The Pleiades are most likely an open cluster.

Accepted Answer

The Pleiades are indeed an open cluster, consisting of relatively young stars that were formed from the same molecular cloud and are gravitationally bound to each other.

Question 8

The age of a star cluster can be determined by its turnoff point.

Accepted Answer

The turnoff point of a star cluster, which is the point on the Hertzsprung-Russell diagram where stars begin to leave the main sequence, can be used to determine the age of the cluster. This is because the turnoff point indicates the stage in evolution that the most massive stars still in the main sequence have reached, which correlates with the cluster's age.

Deck 70: Star Clusters