Question 1

According to the ages of the globular clusters, our Galaxy is about times as old as the solar system.

Accepted Answer

The answer of According to the ages of the globular...

Question 2

To determine the distance to a Cepheid, we must measure its of pulsation.

Accepted Answer

The answer of To determine the distance to a Cepheid,...

Question 3

It would be very unlikely to find a massive, young star out in the halo.

Accepted Answer

A) True 
 B)False

Question 4

Which of these objects have NOT been found in the Galactic Halo?

Accepted Answer

A)   Population II stars
B)   emission nebulae
C)   Cepheid variables
D)   globular clusters
E)   RR Lyrae variablesF) C) and D)
G) B) and D)

Question 5

What are the three main parts of our Galaxy?

Accepted Answer

The disk, ...

Question 6

Which statement about Population II is false?

Accepted Answer

A)   They formed first as the Galaxy formed.
B)   They are made of almost nothing but hydrogen and helium.
C)   At almost five billion years old, our Sun must belong to this older Population.
D)   Their orbits around the Galaxy resemble those of comets.
E)   The globular clusters are their most obvious groupings.F) C) and D)
G) A) and B)

Question 7

Most of the mass of the Milky Way seems to exist in the form of

Accepted Answer

A)   the black hole in the Galactic Center.
B)   dark matter out in the Halo.
C)   hydrogen gas in the disk and spiral arms.
D)   population II stars in the Halo.
E)   population I stars in the disk.F) A) and C)
G) A) and B)

Question 8

This diagram shows the period- luminosity relationship. A Cepheid variable with a period of 5 days will have a luminosity of _ _ solar luminosities.

Accepted Answer

The answer of This diagram shows the period- luminosity relationship....

Question 9

All RR Lyrae stars have about the same

Accepted Answer

A)   luminosity of about 100 Suns.
B)   galactic location and speed.
C)   locations in the centers of globular star clusters.
D)   period of six days.
E)   distance of 32 light-years.F) C) and D)
G) A) and C)

Question 10

Which method relies on the mass of a dark object revealing its presence?

Accepted Answer

A)   temporary brightening of a distant star by a gravity lens
B)   asteroidal occultations
C)   ring occultations
D)   pulsars slowing down irregularly
E)   stellar eclipsesF) A) and B)
G) A) and E)

Question 11

All Cepheid variables discovered so far lie in other galaxies.

Accepted Answer

A) True 
 B)False

Question 12

Harlow Shapley found the Milky Way was

Accepted Answer

A)   much larger than previously thought.
B)   uniformly spherical in shape.
C)   much smaller than previously thought.
D)   centered on the Earth.
E)   rapidly expanding.F) B) and C)
G) C) and E)

Question 13

Which of these is NOT typical of the Galaxy's spiral arms?

Accepted Answer

A)   O and B stars
B)   Population II giants like orange Arcturus
C)   emission nebulae like M42
D)   hot, young blue Population I stars
E)   open clustersF) A) and B)
G) None of the above

Question 14

The density wave theory attempts to explain why the spiral arm structure persists over a long time.

Accepted Answer

A) True 
 B)False

Question 15

Cepheids are good examples of cataclysmic variable stars.

Accepted Answer

A) True 
 B)False

Question 16

What is one of the differences between Cepheids and RR Lyrae variables?

Accepted Answer

A)   Cepheids are giants, but RR Lyrae stars are still on the main sequence.
B)   The pulsations of RR Lyrae stars are much less regular than those of Cepheids.
C)   The RR Lyrae stars have much shorter periods than Cepheids.
D)   The period- luminosity relation holds only for RR Lyrae stars.
E)   All Cepheids have the same brightness, but RR Lyrae stars vary greatly in luminosity.F) A) and D)
G) A) and C)

Question 17

It was _ in the Galactic disk that threw Herschel's model of the size and structure of the Galaxy off badly.

Accepted Answer

The answer of It was _ in the Galactic disk...

Question 18

Open clusters are found in the of our Milky Way Galaxy.

Accepted Answer

disc (or s...

Question 19

What use are 21- cm radio waves to galactic astronomers?

Accepted Answer

A)   They bounce off stars like our Sun to let us precisely measure their distances.
B)   They cut through the dusty cocoons to let us watch star birth.
C)   They pick up the cool, dark matter much better than can optical telescopes.
D)   Their Doppler shifts let us map the motions and locations of gas in the spiral arms.
E)   We can reflect them off the core of the Galaxy.F) All of the above
G) A) and B)

Question 20

Compare the orbital motion of stars in the Galactic disk with those in the halo.

Accepted Answer

Stars in the disk orbit the galactic cen...

Exam 15: The Milky Way Galaxy: a Spiral in Space

The density wave theory attempts to explain why the spiral arm structure persists over a long time.

Correct AnswerverifiedShow Answer

This diagram shows the period- luminosity relationship. A Cepheid variable with a period of 5 days will have a luminosity of _ _ solar luminosities.

Correct AnswerverifiedShow Answer

Open clusters are found in the of our Milky Way Galaxy.

Correct Answerverifieddisc (or s...View AnswerShow Answer

Which of these objects have NOT been found in the Galactic Halo?

Correct AnswerverifiedShow Answer

Which statement about Population II is false?

Correct AnswerverifiedShow Answer

Cepheids are good examples of cataclysmic variable stars.

Correct AnswerverifiedShow Answer

Compare the orbital motion of stars in the Galactic disk with those in the halo.

Correct AnswerverifiedStars in the disk orbit the galactic cen...View AnswerShow Answer

All RR Lyrae stars have about the same

Correct AnswerverifiedShow Answer

What are the three main parts of our Galaxy?

Correct AnswerverifiedThe disk, ...View AnswerShow Answer

It was _ in the Galactic disk that threw Herschel's model of the size and structure of the Galaxy off badly.

Correct AnswerverifiedShow Answer

Most of the mass of the Milky Way seems to exist in the form of

Correct AnswerverifiedShow Answer

What is one of the differences between Cepheids and RR Lyrae variables?

Correct AnswerverifiedShow Answer

All Cepheid variables discovered so far lie in other galaxies.

Correct AnswerverifiedShow Answer

To determine the distance to a Cepheid, we must measure its of pulsation.

Correct AnswerverifiedShow Answer

Which method relies on the mass of a dark object revealing its presence?

Correct AnswerverifiedShow Answer

According to the ages of the globular clusters, our Galaxy is about times as old as the solar system.

Correct AnswerverifiedShow Answer

It would be very unlikely to find a massive, young star out in the halo.

Correct AnswerverifiedShow Answer

Which of these is NOT typical of the Galaxy's spiral arms?

Correct AnswerverifiedShow Answer

Harlow Shapley found the Milky Way was

Correct AnswerverifiedShow Answer

What use are 21- cm radio waves to galactic astronomers?

Correct AnswerverifiedShow Answer

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disc (or s...
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Stars in the disk orbit the galactic cen...
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The disk, ...
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