Question 1

The apparent brightness of a star depends only on its luminosity.

Accepted Answer

A) True 
 B)False

Question 2

The sketch below 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) A 
B) B 
C) C 
D) D 
E) E 
A) A 
B) B 
C) C 
D) D 
E) E

Question 3

Process of Science: How do scientists estimate stellar luminosities?

Accepted Answer

They must find both the bright

Question 4

The sketch below 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 5

Which of the following persons reorganized the spectral classification scheme into the one we use today and personally classified over 400,000 stars?

Accepted Answer

A) Annie Jump Cannon 
B) Williamina Fleming 
C) Cecilia Payne-Gaposchkin 
D) Henry Draper 
E) Edward Pickering 
A) Annie Jump Cannon 
B) Williamina Fleming 
C) Cecilia Payne-Gaposchkin 
D) Henry Draper 
E) Edward Pickering

Question 6

The star Vega has an absolute magnitude of about 4 and an apparent magnitude of about 0.Based on the definitions of absolute and apparent magnitude,we can conclude that

Accepted Answer

A) Vega is nearer than 10 parsecs from Earth. 
B) Vega has a parallax angle of 1/10 arcsecond. 
C) Vega's luminosity is less than that of our Sun. 
D) Vega's surface temperature is cooler than the Sun. 
A) Vega is nearer than 10 parsecs from Earth. 
B) Vega has a parallax angle of 1/10 arcsecond. 
C) Vega's luminosity is less than that of our Sun. 
D) Vega's surface temperature is cooler than the Sun.

Question 7

The sketch below 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 8

Which of the following statements about an open cluster is true?

Accepted Answer

A) All stars in the cluster are approximately the same color. 
B) All stars in the cluster are approximately the same age. 
C) All stars in the cluster have approximately the same mass. 
D) All stars in the cluster will evolve similarly. 
E) There is an approximately equal number of all types of stars in the cluster. 
A) All stars in the cluster are approximately the same color. 
B) All stars in the cluster are approximately the same age. 
C) All stars in the cluster have approximately the same mass. 
D) All stars in the cluster will evolve similarly. 
E) There is an approximately equal number of all types of stars in the cluster.

Question 9

The sketch below 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 10

Which of the following is true about low-mass stars compared to high-mass stars?

Accepted Answer

A) Low-mass stars are cooler and less luminous than high-mass stars. 
B) Low-mass stars are hotter and more 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 cooler and less luminous than high-mass stars. 
B) Low-mass stars are hotter and more 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 11

On the main sequence,stars obtain their energy

Accepted Answer

A) from chemical reactions. 
B) from gravitational contraction. 
C) by converting hydrogen to helium. 
D) by converting helium to carbon,nitrogen,and oxygen. 
E) from nuclear fission. 
A) from chemical reactions. 
B) from gravitational contraction. 
C) by converting hydrogen to helium. 
D) by converting helium to carbon,nitrogen,and oxygen. 
E) from nuclear fission.

Question 12

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

Question 13

Careful measurements reveal that a star maintains a steady apparent brightness at most times,except that at precise intervals of 73 hours the star becomes dimmer for about 2 hours.The most likely explanation is that

Accepted Answer

A) the star is a Cepheid variable. 
B) the star is a member of an eclipsing binary star system. 
C) the star is periodically ejecting gas into space,every 73 hours. 
D) the star is a white dwarf. 
A) the star is a Cepheid variable. 
B) the star is a member of an eclipsing binary star system. 
C) the star is periodically ejecting gas into space,every 73 hours. 
D) the star is a white dwarf.

Question 14

Refer to the choices in the table for the following questions.
  
-Which star has the greatest luminosity?

Accepted Answer

The answer of Refer to the choices in the table...

Question 15

Spectral type,surface temperature,and color all describe the same basic characteristic of a star.

Accepted Answer

A) True 
 B)False

Question 16

The following questions refer to the sketch of the H-R diagram below.Please choose the best answer in each case,i.e. ,choice (a)refers to the entire main sequence,while (c)and (d)refer to only small parts of the main sequence.If choice (c)or (d)offers a better answer to a particular question than (a),use the best choice.You may use the same choice more than once.
  
-Which group includes stars that are burning elements besides hydrogen in their cores?

Accepted Answer

The answer of The following questions refer to the sketch...

Question 17

Stars on the upper left of the H-R diagram are longer lived than those on the lower right.

Accepted Answer

A) True 
 B)False

Question 18

If the distance between us and a star is doubled,with everything else remaining the same,the luminosity

Accepted Answer

A) is decreased by a factor of four,and the apparent brightness is decreased by a factor of four. 
B) is decreased by a factor of two,and the apparent brightness is decreased by a factor of two. 
C) remains the same,but the apparent brightness is decreased by a factor of two. 
D) remains the same,but the apparent brightness is decreased by a factor of four. 
E) is decreased by a factor of four,but the apparent brightness remains the same. 
A) is decreased by a factor of four,and the apparent brightness is decreased by a factor of four. 
B) is decreased by a factor of two,and the apparent brightness is decreased by a factor of two. 
C) remains the same,but the apparent brightness is decreased by a factor of two. 
D) remains the same,but the apparent brightness is decreased by a factor of four. 
E) is decreased by a factor of four,but the apparent brightness remains the same.

Question 19

The following questions refer to the sketch of the H-R diagram below.Please choose the best answer in each case,i.e. ,choice (a)refers to the entire main sequence,while (c)and (d)refer to only small parts of the main sequence.If choice (c)or (d)offers a better answer to a particular question than (a),use the best choice.You may use the same choice more than once.
  
-Which group represents stars that are hot and very bright?

Accepted Answer

The answer of The following questions refer to the sketch...

Question 20

What are the standard units for luminosity?

Accepted Answer

A) watts 
B) joules 
C) Newtons 
D) kilograms 
E) watts per second 
A) watts 
B) joules 
C) Newtons 
D) kilograms 
E) watts per second

Exam 15: Surveying the Stars

The apparent brightness of a star depends only on its luminosity.

The sketch below 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?

Process of Science: How do scientists estimate stellar luminosities?

The sketch below 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?

Which of the following persons reorganized the spectral classification scheme into the one we use today and personally classified over 400,000 stars?

The star Vega has an absolute magnitude of about 4 and an apparent magnitude of about 0.Based on the definitions of absolute and apparent magnitude,we can conclude that

The sketch below 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?

Which of the following statements about an open cluster is true?

The sketch below 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?

Which of the following is true about low-mass stars compared to high-mass stars?

On the main sequence,stars obtain their energy

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?

Careful measurements reveal that a star maintains a steady apparent brightness at most times,except that at precise intervals of 73 hours the star becomes dimmer for about 2 hours.The most likely explanation is that

Refer to the choices in the table for the following questions. -Which star has the greatest luminosity?

Spectral type,surface temperature,and color all describe the same basic characteristic of a star.

Stars on the upper left of the H-R diagram are longer lived than those on the lower right.

If the distance between us and a star is doubled,with everything else remaining the same,the luminosity

What are the standard units for luminosity?

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 and Matter: Reading Messages from the Cosmos

Telescopes: Portals of Discovery

Our Planetary System

Formation of the Solar System

Planetary Geology: Earth and the Other Terrestrial Worlds

Planetary Atmospheres: Earth and the Other Terrestrial Worlds

Jovian Planet Systems

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

Other Planetary Systems: The New Science of Distant Worlds

Our Star

Star Birth

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundations of Modern Cosmology

Galaxy Evolution

The Birth of the Universe

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

Life in the Universe

Celestial Timekeeping and Navigation

Space and Time

Spacetime and Gravity

Building Blocks of the Universe

Filters