Question 1

Our Sun is a star of spectral type .

Accepted Answer

A) S 
B) G 
C) M 
D) F 
A) S 
B) G 
C) M 
D) F

Question 2

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) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 3

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 4

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

Accepted Answer

A) OMKGFBA 
B) OBAGFKM 
C) ABCDEFG 
D) ABFGKMO 
E) OBAFGKM 
A) OMKGFBA 
B) OBAGFKM 
C) ABCDEFG 
D) ABFGKMO 
E) OBAFGKM

Question 5

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. 
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.

Question 6

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

Question 7

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 B 
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 B

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) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 9

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 10

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 galaxy 
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 galaxy

Question 11

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. 
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.

Question 12

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. 
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.

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

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) e 
A) a 
B) b 
C) c 
D) d 
E) 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 years 
A) 10 million years 
B) 10 billion years 
C) 100 billion years

Question 16

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

Accepted Answer

A) True 
 B)False

Question 17

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 18

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

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 A 
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 A

Question 20

What are the standard units for apparent brightness?

Accepted Answer

A) Watts per second 
B) Newtons 
C) Watts per square meter 
D) Watts 
E) Joules 
A) Watts per second 
B) Newtons 
C) Watts per square meter 
D) Watts 
E) Joules

Our Sun is a star of spectral type .

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?

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

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

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

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

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

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?

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?

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

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

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

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

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

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

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

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

What are the standard units for apparent brightness?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

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Exam 12: Surveying the Stars

Our Sun is a star of spectral type .

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?

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

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

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

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

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

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?

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?

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

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

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

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

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

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

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

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

What are the standard units for apparent brightness?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters