Question 1

From Earth, the view of the Milky Way is a thin band of stars across the night sky. The partof the Milky Way Galaxy that is described here is the:

Accepted Answer

A)  Galactic bulge.
B)  spiral arm.
C)  Galactic disk.
D)  Galactic halo.
E)  globular cluster.F) C) and D)
G) A) and E)

Question 2

In age, Population I stars are typically much ________ than those of Population II.

Accepted Answer

The answer of In age, Population I stars are typically...

Question 3

The interstellar ________ absorbs light from stars and makes them appear fainter and redderthan they otherwise would appear.

Accepted Answer

The answer of The interstellar ________ absorbs light from stars...

Question 4

The first attempt to map the Galaxy via star counts was done by:

Accepted Answer

A)  Galileo in 1612.
B)  William Herschel in the late eighteenth century.
C)  Edward Barnard with long exposure photos about 1900.
D)  Harlow Shapley with the RR Lyrae variables in 1920.
E)  Edwin Hubble with the new 100" Mt. Wilson telescope in the 1930s.F) C) and E)
G) A) and B)

Question 5

The region on the H-R diagram where pulsating variables occur is called the:

Accepted Answer

A)  period-luminosity relation.
B)  mass-luminosity relation.
C)  instability strip.
D)  horizontal branch.
E)  main sequence appendix.F) None of the above
G) A) and E)

Question 6

Of what is the Galactic halo presumed to be composed? What evidence supports thisconclusion?

Accepted Answer

The globular clusters are most obvious, ...

Question 7

For what type of object is the period-luminosity relation used for determining distances?

Accepted Answer

A)  RR Lyrae variables
B)  T Tauri variables
C)  Cepheids
D)  cataclysmic variables
E)  planetary nebulaeF) B) and C)
G) A) and E)

Question 8

These objects are no longer considered a good explanation for the dark matter in the Galactichalo.

Accepted Answer

A)  WIMPs
B)  MACHOs
C)  black holes
D)  clouds of cool, neutral hydrogen
E)  brown dwarfsF) A) and B)
G) A) and C)

Question 9

What is the evidence to support the existence of a black hole at the center of the Milky Way?

Accepted Answer

A large amount of activity is present. T...

Question 10

The majority of the mass of the Milky Way lies farther out than the Sun's orbit.

Accepted Answer

A) True 
 B)False

Question 11

How old is the Galaxy? How do we know this?

Accepted Answer

The H-R diagrams of the globular cluster...

Question 12

In the Galactic halo, we do NOT find:

Accepted Answer

A)  tidal streams.
B)  globular clusters.
C)  small satellite galaxies.
D)  spiral arms.
E)  old white dwarfs.F) A) and D)
G) A) and E)

Question 13

Density waves may explain:

Accepted Answer

A)  the lack of blue stars in the Galactic halo.
B)  the random orbits of Galactic halo stars.
C)  the density of red stars in the Galactic bulge.
D)  the spiral arm structure of the Galaxy.
E)  the large number of open clusters in the Galactic halo.F) C) and E)
G) A) and B)

Question 14

How are Cepheids and RR Lyrae stars different?

Accepted Answer

Cepheids are large mass variable stars w...

Question 15

Shapley correctly argued that the rotation of the spiral nebulae proved they could not be verydistant.

Accepted Answer

A) True 
 B)False

Question 16

A pulsating variable star with a period of 10 days would be a Cepheid.

Accepted Answer

A) True 
 B)False

Question 17

Spiral arms are regions of star formation, which accounts for their blue color.

Accepted Answer

A) True 
 B)False

Question 18

Based on star counts, 100 years ago most astronomers thought:

Accepted Answer

A)  we lay about 30,000 ly out from the center of the Galaxy.
B)  we lay near the center of a disk about 10 kpc wide and 2 kpc thick.
C)  we lay in a spiral arm of the largest galaxy in the universe.
D)  we lay near the edge of the only galaxy in the universe.
E)  we were not a part of any structure larger than the known solar system.F) A) and B)
G) A) and C)

Question 19

What use are 21 cm radio waves to galactic astronomers?

Accepted Answer

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

Question 20

The period-luminosity relation is critical in finding distances with:

Accepted Answer

A)  RR Lyrae stars.
B)  trigonometric parallaxes.
C)  spectroscopic parallaxes.
D)  Cepheid variables.
E)  pulsars.F) B) and E)
G) D) and E)

Exam 23: The Milky Way Galaxy: a Spiral in Space

Based on star counts, 100 years ago most astronomers thought:

Correct AnswerverifiedShow Answer

These objects are no longer considered a good explanation for the dark matter in the Galactichalo.

Correct AnswerverifiedShow Answer

The first attempt to map the Galaxy via star counts was done by:

Correct AnswerverifiedShow Answer

In age, Population I stars are typically much ________ than those of Population II.

Correct AnswerverifiedShow Answer

The interstellar ________ absorbs light from stars and makes them appear fainter and redderthan they otherwise would appear.

Correct AnswerverifiedShow Answer

What is the evidence to support the existence of a black hole at the center of the Milky Way?

Correct AnswerverifiedA large amount of activity is present. T...View AnswerShow Answer

What use are 21 cm radio waves to galactic astronomers?

Correct AnswerverifiedShow Answer

In the Galactic halo, we do NOT find:

Correct AnswerverifiedShow Answer

The period-luminosity relation is critical in finding distances with:

Correct AnswerverifiedShow Answer

The region on the H-R diagram where pulsating variables occur is called the:

Correct AnswerverifiedShow Answer

Density waves may explain:

Correct AnswerverifiedShow Answer

From Earth, the view of the Milky Way is a thin band of stars across the night sky. The partof the Milky Way Galaxy that is described here is the:

Correct AnswerverifiedShow Answer

For what type of object is the period-luminosity relation used for determining distances?

Correct AnswerverifiedShow Answer

The majority of the mass of the Milky Way lies farther out than the Sun's orbit.

Correct AnswerverifiedShow Answer

How old is the Galaxy? How do we know this?

Correct AnswerverifiedThe H-R diagrams of the globular cluster...View AnswerShow Answer

A pulsating variable star with a period of 10 days would be a Cepheid.

Correct AnswerverifiedShow Answer

Of what is the Galactic halo presumed to be composed? What evidence supports thisconclusion?

Correct AnswerverifiedThe globular clusters are most obvious, ...View AnswerShow Answer

Spiral arms are regions of star formation, which accounts for their blue color.

Correct AnswerverifiedShow Answer

Shapley correctly argued that the rotation of the spiral nebulae proved they could not be verydistant.

Correct AnswerverifiedShow Answer

How are Cepheids and RR Lyrae stars different?

Correct AnswerverifiedCepheids are large mass variable stars w...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A large amount of activity is present. T...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The H-R diagrams of the globular cluster...
View Answer

Correct Answer
verified

Correct Answer
verified
The globular clusters are most obvious, ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Cepheids are large mass variable stars w...
View Answer