Question 1

Which of the following are generally NOT found in our galaxy's halo?

Accepted Answer

A)  globular clusters
B)  planetary nebulae
C)  RR Lyrae stars
D)  stars with high percentages of heavy elements
E)  low-mass main-sequence stars

Question 2

The Sun has 2 percent of its mass in heavy elements (those elements that are not hydrogen and helium).What does this tell us about chemical enrichment in the galaxy?

Accepted Answer

The chemical composition of stars is det...

Question 3

We can estimate the mass of the central black hole in the Milky Way by measuring the orbital speeds of stars near it.

Accepted Answer

A) True 
 B)False

Question 4

Open clusters are only found in the disk of the Milky Way;globular clusters are only found in the halo of the Milky Way.

Accepted Answer

A) True 
 B)False  False

Question 5

A dwarf galaxy is currently being ripped apart and accreted onto the Milky Way.

Accepted Answer

A) True 
 B)False

Question 6

What observed property of the Milky Way suggests that it contains a large amount of matter not in the form of stars?

Accepted Answer

A)  the rotation curve
B)  the velocities of the open star clusters
C)  the number and shape of the spiral arms
D)  the thickness of the disk
E)  the presence of a black hole at the galactic center

Question 7

The youngest disk stars are found in a very thin plane in the disk.

Accepted Answer

A) True 
 B)False

Question 8

Halo stars near the Sun are distinguished from disk stars by what characteristics?

Accepted Answer

A)  low chemical abundances and low relative velocities
B)  high chemical abundances and high relative velocities
C)  low chemical abundances and high relative velocities
D)  high chemical abundances and low relative velocities
E)  equal chemical abundances and high relative velocities

Question 9

On average,we expect that __________ stars have the __________ percentage of heavy elements.

Accepted Answer

A)  older;highest
B)  disk;lowest
C)  bulge;lowest
D)  halo;highest
E)  younger;highest

Question 10

The Milky Way has both a thin and thick disk of stars.Which one of the following statements about them is FALSE?

Accepted Answer

A)  The thin disk stars on average are younger than the thick disk stars.
B)  Molecular clouds are distributed more like the thin disk stars rather than the thick disk stars.
C)  The thin disk stars on average have lower abundances of heavy elements than the thick disk stars.
D)  The thick disk stars may be older thin disk stars that have higher upward velocities because they have gravitationally interacted more with molecular clouds in the spiral arms.
E)  The thick disk may have formed when a small dwarf galaxy merged with the Milky Way. C

Question 11

Describe the population of globular star clusters in the Milky Way: how many are there,where do they reside in the Milky Way,and how do their ages and chemical abundances compare to the Sun?

Accepted Answer

The Milky Way contains over 150 globular...

Question 12

The chemical composition of a star's atmosphere tells us:

Accepted Answer

A)  how much nuclear burning has gone on in the star
B)  the star's evolutionary stage
C)  how many planets have fallen onto the star in its lifetime
D)  the chemical composition of the cloud from which the star formed
E)  the amount of heavy elements the entire galaxy had when the star was formed

Question 13

Which of these galaxies is most like our own,and what is the name for the type of the galaxy we live in?

Accepted Answer

A)  Galaxy A;giant elliptical
B)  Galaxy A: nonbarred spiral
C)  Galaxy B: barred spiral
D)  Galaxy B: irregular
E)  Galaxy B: lenticular

Question 14

The presence of dwarf galaxies around the Milky Way supports what picture of our galaxy's formation?

Accepted Answer

A)  The galaxy formed by the merger of two large galaxies,which scattered their dwarf companions to large distances.
B)  The galaxy originally formed with no dark matter but gained its dark matter by the absorption of smaller dwarf systems.
C)  The galaxy formed in a giant explosion caused by the violent collisions of clouds of dark matter.
D)  The galaxy formed a long time ago and has been passively evolving since.
E)  The galaxy formed by the merger of smaller systems.

Question 15

You find a star orbiting about the center of the galaxy at a speed of 220 km/s at a distance of 15 kpc.How much mass is within the orbit of that star? You can assume the star is on a circular orbit around the center of the Milky Way.

Accepted Answer

The mass is derived from the equation M ...

Question 16

Where are the most metal-rich stars found in the Milky Way?

Accepted Answer

A)  in the disk near the Sun
B)  near the center
C)  in the halo
D)  in globular clusters
E)  in old open clusters

Question 17

What type of standard candle is used to determine distances to globular clusters?

Accepted Answer

A)  O-type main-sequence stars
B)  Cepheid variable stars
C)  T Tauri stars
D)  Type I supernovae
E)  RR Lyrae stars

Question 18

How do we think the central black hole in the galaxy primarily grew to its current mass?

Accepted Answer

A)  ordinary stellar evolution of massive stars
B)  merger of close binary stars
C)  shock waves from supernova explosions
D)  dark matter clumping together
E)  accretion of nearby gas E

Question 19

If you found a star cluster that was 13 billion years old and whose stars had fractions of heavy elements that were 100 times less than that in the Sun,what type of star cluster would this be and where would it most likely be located?

Accepted Answer

A)  an open cluster that is likely to be in the disk
B)  an open cluster that is likely to be in the stellar halo
C)  a globular cluster that is likely to be in the thin disk
D)  a globular cluster that is likely to be in the stellar halo
E)  a globular cluster that is likely to be in the central bar

Question 20

Describe the differences between the ages and chemical abundances of globular and open star clusters.

Accepted Answer

Globular clusters are very old,12-13 bil...

Exam 21: The Milky Waya Normal Spiral Galaxy

Which of the following are generally NOT found in our galaxy's halo?

Correct AnswerverifiedShow Answer

The Sun has 2 percent of its mass in heavy elements (those elements that are not hydrogen and helium).What does this tell us about chemical enrichment in the galaxy?

Correct AnswerverifiedThe chemical composition of stars is det...View AnswerShow Answer

We can estimate the mass of the central black hole in the Milky Way by measuring the orbital speeds of stars near it.

Correct AnswerverifiedShow Answer

Open clusters are only found in the disk of the Milky Way;globular clusters are only found in the halo of the Milky Way.

Correct AnswerverifiedFalse

A dwarf galaxy is currently being ripped apart and accreted onto the Milky Way.

Correct AnswerverifiedShow Answer

What observed property of the Milky Way suggests that it contains a large amount of matter not in the form of stars?

Correct AnswerverifiedShow Answer

The youngest disk stars are found in a very thin plane in the disk.

Correct AnswerverifiedShow Answer

Halo stars near the Sun are distinguished from disk stars by what characteristics?

Correct AnswerverifiedShow Answer

On average,we expect that __________ stars have the __________ percentage of heavy elements.

Correct AnswerverifiedShow Answer

The Milky Way has both a thin and thick disk of stars.Which one of the following statements about them is FALSE?

Correct AnswerverifiedC

Describe the population of globular star clusters in the Milky Way: how many are there,where do they reside in the Milky Way,and how do their ages and chemical abundances compare to the Sun?

Correct AnswerverifiedThe Milky Way contains over 150 globular...View AnswerShow Answer

The chemical composition of a star's atmosphere tells us:

Correct AnswerverifiedShow Answer

Which of these galaxies is most like our own,and what is the name for the type of the galaxy we live in?

Correct AnswerverifiedShow Answer

The presence of dwarf galaxies around the Milky Way supports what picture of our galaxy's formation?

Correct AnswerverifiedShow Answer

You find a star orbiting about the center of the galaxy at a speed of 220 km/s at a distance of 15 kpc.How much mass is within the orbit of that star? You can assume the star is on a circular orbit around the center of the Milky Way.

Correct AnswerverifiedThe mass is derived from the equation M ...View AnswerShow Answer

Where are the most metal-rich stars found in the Milky Way?

Correct AnswerverifiedShow Answer

What type of standard candle is used to determine distances to globular clusters?

Correct AnswerverifiedShow Answer

How do we think the central black hole in the galaxy primarily grew to its current mass?

Correct AnswerverifiedE

If you found a star cluster that was 13 billion years old and whose stars had fractions of heavy elements that were 100 times less than that in the Sun,what type of star cluster would this be and where would it most likely be located?

Correct AnswerverifiedShow Answer

Describe the differences between the ages and chemical abundances of globular and open star clusters.

Correct AnswerverifiedGlobular clusters are very old,12-13 bil...View AnswerShow Answer

Correct Answer
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The chemical composition of stars is det...
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False

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On average,we expect that stars have the percentage of heavy elements.

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C

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The Milky Way contains over 150 globular...
View Answer

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The mass is derived from the equation M ...
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E

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Globular clusters are very old,12-13 bil...
View Answer