Question 1

Some stars are cool enough to have molecules in their atmosphere.

Accepted Answer

A) True 
 B)False

Question 2

Star X has an apparent magnitude of 3, and star Y has an apparent magnitude of 8. How do they compare in observed brightness?

Accepted Answer

A)  Star Y is 5 times brighter than star X.
B)  Star Y is 100 times brighter than star X.
C)  Star X is 5 times brighter than star Y.
D)  Star X is 100 times brighter than star Y.E) A) and B)
F) A) and C)

Question 3

If the distance between us and a star is doubled, its apparent brightness will decrease by a factor of four.

Accepted Answer

A) True 
 B)False

Question 4

Main sequence stars have radii ranging from about 0.03 solar radius to 30 solar radius.

Accepted Answer

A) True 
 B)False

Question 5

Our Sun is a star of spectral type .

Accepted Answer

A)  S
B)  G
C)  M
D)  FE) C) and D)
F) None of the above

Question 6

The sketch above shows groups of stars on the H- R diagram, labeled (a) through (e) ; note that (a) represents the entire main sequence while (c) and (d) represent only small parts of the main sequence. Which group represents stars with the longest main- sequence lifetimes?

Accepted Answer

A)  a
B)  b
C)  c
D)  d
E)  eF) B) and E)
G) C) and D)

Question 7

The youngest star cluster is the one where the brightest main- sequence stars are

Accepted Answer

A)  B stars.
B)  G stars.
C)  A stars.
D)  M stars.
E)  O stars.F) A) and B)
G) A) and C)

Question 8

The sketch above shows groups of stars on the H- R diagram, labeled (a) through (e) ; note that (a) represents the entire main sequence while (c) and (d) represent only small parts of the main sequence. Which group represents stars fusing hydrogen in their cores?

Accepted Answer

A)  a
B)  b
C)  c
D)  d
E)  eF) A) and C)
G) All of the above

Question 9

All stars are born with the same basic composition, yet stars can look quite different from one another. Which two factors primarily determine the characteristics of a star?

Accepted Answer

A)  its mass and its surface temperature
B)  its mass and its stage of life
C)  its apparent brightness and its distance
D)  its apparent brightness and its luminosity
E)  its age and its location in the galaxyF) A) and E)
G) A) and D)

Question 10

The size of the Earth's orbit is doubled. This will allow the parallaxes of more distant stars to be measured.

Accepted Answer

A) True 
 B)False

Question 11

Confusing Terminology in Science: Scientists' love of jargon and acronyms often confounds the public and makes it impossible for them to read scientific literature. Use the example of spectral types introduced in this chapter (i.e., the Sun is a "G2" star)as a case study in jargon. What is the historical origin of the spectral types? Why are the letters in a confusing, non- alphabetical order? Why do you think astronomers persist in using spectral types? Do you think astronomers should drop this notation, and, if so, what should replace it?

Accepted Answer

The historical origin of spectral types ...

Question 12

Which of the following comparisons between low- mass stars and high- mass main- sequence stars is true?

Accepted Answer

A)  Low- mass stars are hotter and more luminous than high- mass stars.
B)  Low- mass stars are cooler and less luminous than high- mass stars.
C)  Low- mass stars are cooler but more luminous than high- mass stars.
D)  Low- mass stars are hotter but less luminous than high- mass stars.
E)  Low- mass stars have the same temperature and luminosity as high- mass stars.F) C) and D)
G) A) and D)

Question 13

Which of the following is the most numerous type of main- sequence star?

Accepted Answer

A)  an M star
B)  an F star
C)  an O star
D)  a G star
E)  an A starF) A) and E)
G) B) and D)

Question 14

From hottest to coolest, the order of the spectral types of stars is .

Accepted Answer

A)  OMKGFBA
B)  OBAGFKM
C)  ABCDEFG
D)  ABFGKMO
E)  OBAFGKMF) A) and C)
G) A) and E)

Question 15

What is the approximate age of a star cluster where the brightest main sequence stars are G stars?

Accepted Answer

A)  10 million years
B)  10 billion years
C)  100 billion yearsD) All of the above
E) B) and C)

Question 16

The sketch above shows groups of stars on the H- R diagram, labeled (a) through (e) ; note that (a) represents the entire main sequence while (c) and (d) represent only small parts of the main sequence. Which group represents stars that are extremely bright and emit most of their radiation as ultraviolet light?

Accepted Answer

A)  a
B)  b
C)  c
D)  d
E)  eF) None of the above
G) C) and D)

Question 17

What are the standard units for apparent brightness?

Accepted Answer

A)  Watts per second
B)  Newtons
C)  Watts per square meter
D)  Watts
E)  JoulesF) A) and C)
G) A) and D)

Question 18

According to the inverse square law of light, how will the apparent brightness of an object change if its distance to us triples?

Accepted Answer

A)  Its apparent brightness will increase by a factor of 9.
B)  Its apparent brightness will increase by a factor of 3.
C)  Its apparent brightness will decrease by a factor of 3.
D)  Its apparent brightness will decrease by a factor of 9.E) B) and D)
F) None of the above

Question 19

Star A is identical to Star B, except that Star A is twice as far from us as Star B. Therefore, _ .

Accepted Answer

A)  both stars have the same luminosity, but the apparent brightness of Star B is four times that of Star A
B)  both stars have the same luminosity, but the apparent brightness of Star A is four times that of Star B
C)  both stars have the same luminosity, but the apparent brightness of Star B is twice that of Star A
D)  both stars have the same apparent brightness, but the luminosity of Star B is four times that of Star AE) B) and D)
F) None of the above

Question 20

If Star A is closer to us than Star B, then Star A's parallax angle is _ .

Accepted Answer

A)  smaller than that of Star B
B)  larger than that of Star B
C)  fewer parsecs than that of Star B
D)  hotter than that of Star BE) A) and C)
F) B) and D)

Exam 12: Surveying the Stars

If the distance between us and a star is doubled, its apparent brightness will decrease by a factor of four.

Correct Answer
verified

Which of the following is the most numerous type of main- sequence star?

Correct Answer
verified

Our Sun is a star of spectral type .

Correct Answer
verified

Correct Answer
verified

The youngest star cluster is the one where the brightest main- sequence stars are

Correct Answer
verified

What is the approximate age of a star cluster where the brightest main sequence stars are G stars?

Correct Answer
verified

Some stars are cool enough to have molecules in their atmosphere.

Correct Answer
verified

Star X has an apparent magnitude of 3, and star Y has an apparent magnitude of 8. How do they compare in observed brightness?

Correct Answer
verified

Main sequence stars have radii ranging from about 0.03 solar radius to 30 solar radius.

Correct Answer
verified

The sketch above shows groups of stars on the H- R diagram, labeled (a) through (e) ; note that (a) represents the entire main sequence while (c) and (d) represent only small parts of the main sequence. Which group represents stars fusing hydrogen in their cores?

Correct Answer
verified

Which of the following comparisons between low- mass stars and high- mass main- sequence stars is true?

Correct Answer
verified

What are the standard units for apparent brightness?

Correct Answer
verified

From hottest to coolest, the order of the spectral types of stars is .

Correct Answer
verified

The sketch above shows groups of stars on the H- R diagram, labeled (a) through (e) ; note that (a) represents the entire main sequence while (c) and (d) represent only small parts of the main sequence. Which group represents stars with the longest main- sequence lifetimes?

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
The historical origin of spectral types ...
View Answer

The size of the Earth's orbit is doubled. This will allow the parallaxes of more distant stars to be measured.

Correct Answer
verified

If Star A is closer to us than Star B, then Star A's parallax angle is _ .

Correct Answer
verified

According to the inverse square law of light, how will the apparent brightness of an object change if its distance to us triples?

Correct Answer
verified

Star A is identical to Star B, except that Star A is twice as far from us as Star B. Therefore, _ .

Correct Answer
verified

All stars are born with the same basic composition, yet stars can look quite different from one another. Which two factors primarily determine the characteristics of a star?

Correct Answer
verified

Exam 12: Surveying the Stars

If the distance between us and a star is doubled, its apparent brightness will decrease by a factor of four.

Correct AnswerverifiedShow Answer

Which of the following is the most numerous type of main- sequence star?

Correct AnswerverifiedShow Answer

Our Sun is a star of spectral type .

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The youngest star cluster is the one where the brightest main- sequence stars are

Correct AnswerverifiedShow Answer

What is the approximate age of a star cluster where the brightest main sequence stars are G stars?

Correct AnswerverifiedShow Answer

Some stars are cool enough to have molecules in their atmosphere.

Correct AnswerverifiedShow Answer

Star X has an apparent magnitude of 3, and star Y has an apparent magnitude of 8. How do they compare in observed brightness?

Correct AnswerverifiedShow Answer

Main sequence stars have radii ranging from about 0.03 solar radius to 30 solar radius.

Correct AnswerverifiedShow Answer

The sketch above shows groups of stars on the H- R diagram, labeled (a) through (e) ; note that (a) represents the entire main sequence while (c) and (d) represent only small parts of the main sequence. Which group represents stars fusing hydrogen in their cores?

Correct AnswerverifiedShow Answer

Which of the following comparisons between low- mass stars and high- mass main- sequence stars is true?

Correct AnswerverifiedShow Answer

What are the standard units for apparent brightness?

Correct AnswerverifiedShow Answer

From hottest to coolest, the order of the spectral types of stars is .

Correct AnswerverifiedShow Answer

The sketch above shows groups of stars on the H- R diagram, labeled (a) through (e) ; note that (a) represents the entire main sequence while (c) and (d) represent only small parts of the main sequence. Which group represents stars with the longest main- sequence lifetimes?

Correct AnswerverifiedShow Answer

Correct AnswerAnswered by ExamLex AIThe historical origin of spectral types ...View AnswerShow Answer

The size of the Earth's orbit is doubled. This will allow the parallaxes of more distant stars to be measured.

Correct AnswerverifiedShow Answer

If Star A is closer to us than Star B, then Star A's parallax angle is _ .

Correct AnswerverifiedShow Answer

According to the inverse square law of light, how will the apparent brightness of an object change if its distance to us triples?

Correct AnswerverifiedShow Answer

Star A is identical to Star B, except that Star A is twice as far from us as Star B. Therefore, _ .

Correct AnswerverifiedShow Answer

All stars are born with the same basic composition, yet stars can look quite different from one another. Which two factors primarily determine the characteristics of a star?

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
The historical origin of spectral types ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
verified

Correct Answer
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