Question 1

Why do O stars exhibit weak hydrogen absorption lines?

Accepted Answer

A) At these high temperatures, nearly all the hydrogen is ionized, and is therefore unable to interact with light. 
B) O stars contain very little hydrogen. 
C) O stars are too cool to excite hydrogen atoms to the first energy level from which they can then absorb visible wavelengths of light. 
A) At these high temperatures, nearly all the hydrogen is ionized, and is therefore unable to interact with light. 
B) O stars contain very little hydrogen. 
C) O stars are too cool to excite hydrogen atoms to the first energy level from which they can then absorb visible wavelengths of light.

Question 2

A star with an apparent magnitude of 10 appears fainter than a star with an apparent magnitude of 9.

Accepted Answer

A) True 
 B)False

Question 3

Which star is the hottest star?

Accepted Answer

A) O 
B) G 
C) M 
D) A 
E) Can't tell from information provided. 
A) O 
B) G 
C) M 
D) A 
E) Can't tell from information provided.

Question 4

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 the most common type of stars?

Accepted Answer

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

Question 5

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 cool and dim?

Accepted Answer

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

Question 6

What is the spectral type of a star with very strong hydrogen absorption lines?

Accepted Answer

A) G 
B) B 
C) A 
D) F 
A) G 
B) B 
C) A 
D) F

Question 7

Which of the following statements about globular clusters is true?

Accepted Answer

A) All stars in the cluster have approximately the same mass. 
B) There is an approximately equal number of all types of stars in the cluster. 
C) Most stars in the cluster are yellow or reddish in color. 
D) All stars in the cluster are approximately at the same stage in their evolution. 
E) Most of the stars in the cluster are younger than 10 billion years. 
A) All stars in the cluster have approximately the same mass. 
B) There is an approximately equal number of all types of stars in the cluster. 
C) Most stars in the cluster are yellow or reddish in color. 
D) All stars in the cluster are approximately at the same stage in their evolution. 
E) Most of the stars in the cluster are younger than 10 billion years.

Question 8

The choices below each describe the appearance of an H- R diagram for a different star cluster. Which cluster is the youngest?

Accepted Answer

A) The diagram shows no main- sequence stars at all, but it has numerous supergiants and white dwarfs. 
B) The diagram shows main- sequence stars of every spectral type except O, along with a few giants and supergiants. 
C) The diagram shows main- sequence stars of all the spectral types except O and B, along with a few giants and supergiants. 
D) The diagram shows main- sequence stars of spectral types G, K, and M, along with numerous giants and white dwarfs. 
A) The diagram shows no main- sequence stars at all, but it has numerous supergiants and white dwarfs. 
B) The diagram shows main- sequence stars of every spectral type except O, along with a few giants and supergiants. 
C) The diagram shows main- sequence stars of all the spectral types except O and B, along with a few giants and supergiants. 
D) The diagram shows main- sequence stars of spectral types G, K, and M, along with numerous giants and white dwarfs.

Question 9

A star of spectral type B with a mass of 10 times the mass of the Sun lives approximately how long on the main sequence?

Accepted Answer

A) 10,000 years 
B) 10 million years 
C) 10 billion years 
D) 1,000 years 
E) 1 billion years 
A) 10,000 years 
B) 10 million years 
C) 10 billion years 
D) 1,000 years 
E) 1 billion years

Question 10

-A star is observed with a surface temperature of 3,000 K and a luminosity of 10-2 solar. What is the approximate radius of this star?

Accepted Answer

A) 1 solar radius 
B) 0)3 solar radius 
C) 0)1 solar radius 
D) The radius cannot be determined. 
A) 1 solar radius 
B) 0)3 solar radius 
C) 0)1 solar radius 
D) The radius cannot be determined.

Question 11

On a Hertzsprung- Russell diagram, where on the main sequence would you find stars that have the greatest mass?

Accepted Answer

A) upper right 
B) lower right 
C) upper left 
D) lower left 
A) upper right 
B) lower right 
C) upper left 
D) lower left

Question 12

Which of the following stars has a spectrum that peaks at the shortest wavelength?

Accepted Answer

A) a blue star 
B) a red star 
C) a yellow star 
A) a blue star 
B) a red star 
C) a yellow star

Question 13

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 have no ongoing nuclear fusion?

Accepted Answer

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

Question 14

Observing Stellar Evolution: Stars evolve on timescales of millions to billions of years, making it impossible for astronomers to follow the life- cycle of any individual star. Explain how astronomers overcome this limitation. Be sure to discuss the important role that observations of star clusters play in revealing the evolution of stars.

Accepted Answer

Astronomers overcome the limitation of n

Question 15

What is the approximate surface temperature of an F star?

Accepted Answer

A) 12,000 K 
B) 7,000 K 
C) 5,000 K 
D) 6,000 K 
A) 12,000 K 
B) 7,000 K 
C) 5,000 K 
D) 6,000 K

Question 16

Blue stars are always more luminous than red stars.

Accepted Answer

A) True 
 B)False

Question 17

Two separate pairs of binary stars are observed. The separation of the pairs is identical, but the orbital period of Pair X is 4 times the orbital period of Pair Y. How does the total mass of the stars in Pair X compare to the total mass of the stars in Pair Y?

Accepted Answer

A) Pair Y has a total mass 2 times greater than Pair X. 
B) Pair Y has a total mass 16 times greater than Pair X. 
C) Pair X has a total mass 16 times greater than Pair Y. 
D) Pair X has a total mass 2 times greater than Pair Y. 
A) Pair Y has a total mass 2 times greater than Pair X. 
B) Pair Y has a total mass 16 times greater than Pair X. 
C) Pair X has a total mass 16 times greater than Pair Y. 
D) Pair X has a total mass 2 times greater than Pair Y.

Question 18

On an H- R diagram, stellar radii .

Accepted Answer

A) are greatest in the lower left and least in the upper right 
B) decrease from left to right 
C) are impossible to determine 
D) increase diagonally from the lower left to the upper right 
A) are greatest in the lower left and least in the upper right 
B) decrease from left to right 
C) are impossible to determine 
D) increase diagonally from the lower left to the upper right

Question 19

Each choice below lists a spectral type and luminosity class for a star. Which one is a red supergiant?

Accepted Answer

A) spectral type M2, luminosity class I 
B) spectral type O9, luminosity class I 
C) spectral type M1, luminosity class V 
D) spectral type G2, luminosity class V 
A) spectral type M2, luminosity class I 
B) spectral type O9, luminosity class I 
C) spectral type M1, luminosity class V 
D) spectral type G2, luminosity class V

Question 20

Sirius is a star with spectral type A and Rigel is a star with spectral type B. What can we conclude?

Accepted Answer

A) Rigel has a higher surface temperature than Sirius. 
B) Rigel has a higher core temperature than Sirius. 
C) Sirius has a higher surface temperature than Rigel. 
D) Sirius has a higher core temperature than Rigel. 
A) Rigel has a higher surface temperature than Sirius. 
B) Rigel has a higher core temperature than Sirius. 
C) Sirius has a higher surface temperature than Rigel. 
D) Sirius has a higher core temperature than Rigel.

Why do O stars exhibit weak hydrogen absorption lines?

A star with an apparent magnitude of 10 appears fainter than a star with an apparent magnitude of 9.

Which star is the hottest star?

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 the most common type of stars?

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 cool and dim?

What is the spectral type of a star with very strong hydrogen absorption lines?

Which of the following statements about globular clusters is true?

The choices below each describe the appearance of an H- R diagram for a different star cluster. Which cluster is the youngest?

A star of spectral type B with a mass of 10 times the mass of the Sun lives approximately how long on the main sequence?

-A star is observed with a surface temperature of 3,000 K and a luminosity of 10-2 solar. What is the approximate radius of this star?

On a Hertzsprung- Russell diagram, where on the main sequence would you find stars that have the greatest mass?

Which of the following stars has a spectrum that peaks at the shortest wavelength?

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 have no ongoing nuclear fusion?

What is the approximate surface temperature of an F star?

Blue stars are always more luminous than red stars.

Two separate pairs of binary stars are observed. The separation of the pairs is identical, but the orbital period of Pair X is 4 times the orbital period of Pair Y. How does the total mass of the stars in Pair X compare to the total mass of the stars in Pair Y?

On an H- R diagram, stellar radii .

Each choice below lists a spectral type and luminosity class for a star. Which one is a red supergiant?

Sirius is a star with spectral type A and Rigel is a star with spectral type B. What can we conclude?

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Exam 12: Surveying the Stars

Why do O stars exhibit weak hydrogen absorption lines?

A star with an apparent magnitude of 10 appears fainter than a star with an apparent magnitude of 9.

Which star is the hottest star?

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 the most common type of stars?

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 cool and dim?

What is the spectral type of a star with very strong hydrogen absorption lines?

Which of the following statements about globular clusters is true?

The choices below each describe the appearance of an H- R diagram for a different star cluster. Which cluster is the youngest?

A star of spectral type B with a mass of 10 times the mass of the Sun lives approximately how long on the main sequence?

-A star is observed with a surface temperature of 3,000 K and a luminosity of 10-2 solar. What is the approximate radius of this star?

On a Hertzsprung- Russell diagram, where on the main sequence would you find stars that have the greatest mass?

Which of the following stars has a spectrum that peaks at the shortest wavelength?

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 have no ongoing nuclear fusion?

What is the approximate surface temperature of an F star?

Blue stars are always more luminous than red stars.

Two separate pairs of binary stars are observed. The separation of the pairs is identical, but the orbital period of Pair X is 4 times the orbital period of Pair Y. How does the total mass of the stars in Pair X compare to the total mass of the stars in Pair Y?

On an H- R diagram, stellar radii .

Each choice below lists a spectral type and luminosity class for a star. Which one is a red supergiant?

Sirius is a star with spectral type A and Rigel is a star with spectral type B. What can we conclude?

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