Question 1

Which of the following cannot be true of the very first stars formed in the Universe?

Accepted Answer

A)  Some may have all exploded as supernovae by now. 
B)  Some may have formed in large clusters. 
C)  Some may have formed singly, in isolation from one another. 
D)  Some may still exist in the Milky Way today. 
E)  Some may have had rocky planets around them. 
A)  Some may have all exploded as supernovae by now. 
B)  Some may have formed in large clusters. 
C)  Some may have formed singly, in isolation from one another. 
D)  Some may still exist in the Milky Way today. 
E)  Some may have had rocky planets around them. E

Question 2

How was Edwin Hubble able to use his discovery of Cepheids in Andromeda to prove that the "spiral nebulae" were actually galaxies external to the Milky Way?

Accepted Answer

A)  There are no Cepheids in the Milky Way, so his discovery proved that Andromeda had to be in another galaxy. 
B)  He measured the parallaxes of the Cepheids in Andromeda to determine their distances. He showed that Andromeda was far outside the Milky Way Galaxy. 
C)  He used main-sequence fitting to determine the distances to the Cepheids. He showed that Andromeda was far outside the Milky Way Galaxy. 
D)  From the period-luminosity relation for Cepheids, he was able to determine the distance to Andromeda. He showed that it was far outside the Milky Way Galaxy. 
E)  As a Cepheid is a type of luminous galaxy, Hubble's discovery of Cepheids in Andromeda proved that it was a separate galaxy from the Milky Way. 
A)  There are no Cepheids in the Milky Way, so his discovery proved that Andromeda had to be in another galaxy. 
B)  He measured the parallaxes of the Cepheids in Andromeda to determine their distances. He showed that Andromeda was far outside the Milky Way Galaxy. 
C)  He used main-sequence fitting to determine the distances to the Cepheids. He showed that Andromeda was far outside the Milky Way Galaxy. 
D)  From the period-luminosity relation for Cepheids, he was able to determine the distance to Andromeda. He showed that it was far outside the Milky Way Galaxy. 
E)  As a Cepheid is a type of luminous galaxy, Hubble's discovery of Cepheids in Andromeda proved that it was a separate galaxy from the Milky Way. D

Question 3

Spiral galaxies have more gas, dust, and young stars than elliptical galaxies.

Accepted Answer

A) True 
 B)False  True

Question 4

What two observable properties of a Cepheid variable are directly related to one another?

Accepted Answer

A)  The period between its peaks of brightness and its luminosity 
B)  The period between its peaks of brightness and its distance 
C)  Its luminosity and its mass 
D)  Its mass and its distance 
A)  The period between its peaks of brightness and its luminosity 
B)  The period between its peaks of brightness and its distance 
C)  Its luminosity and its mass 
D)  Its mass and its distance

Question 5

Suppose that we look at a photograph of many galaxies. Assuming that all galaxies formed at about the same time, which galaxy in the picture is the youngest?

Accepted Answer

A)  the one that is reddest in color 
B)  the one that is bluest in color 
C)  the one that is farthest away 
D)  the one that is closest to us 
E)  the one that appears smallest in size 
A)  the one that is reddest in color 
B)  the one that is bluest in color 
C)  the one that is farthest away 
D)  the one that is closest to us 
E)  the one that appears smallest in size

Question 6

Why are white dwarf supernovae more useful than massive star supernovae for measuring cosmic distances?

Accepted Answer

A)  White dwarf supernovae all have roughly the same true peak luminosity, while massive supernovae come in a wide range of peak luminosities. 
B)  We can see only white dwarf supernovae in distant galaxies, not massive star supernovae. 
C)  White dwarf supernovae are much more common than massive star supernovae. 
D)  White dwarf supernovae follow a period-luminosity relation, while massive supernovae do not. 
A)  White dwarf supernovae all have roughly the same true peak luminosity, while massive supernovae come in a wide range of peak luminosities. 
B)  We can see only white dwarf supernovae in distant galaxies, not massive star supernovae. 
C)  White dwarf supernovae are much more common than massive star supernovae. 
D)  White dwarf supernovae follow a period-luminosity relation, while massive supernovae do not.

Question 7

Most active galactic nuclei are at large distances from us; relatively few nearby galaxies harbor active galactic nuclei. What does this imply?

Accepted Answer

A)  Massive black holes existed only when the universe was young and no longer exist today. 
B)  Active galactic nuclei tend to become less active as they age. 
C)  Active galactic nuclei can form only at large distances from the Milky Way. 
D)  The jets seen in many active galactic nuclei must cause them to move far away from us. 
A)  Massive black holes existed only when the universe was young and no longer exist today. 
B)  Active galactic nuclei tend to become less active as they age. 
C)  Active galactic nuclei can form only at large distances from the Milky Way. 
D)  The jets seen in many active galactic nuclei must cause them to move far away from us.

Question 8

Dr. X believes that the Hubble constant is H₀ = 20 km/s/Mly while Dr. Y believes it is H₀ = 24 km/s/Mly. Which statement below automatically follows?

Accepted Answer

A)  Dr. X believes that the universe is expanding, but Dr. Y does not. 
B)  Dr. X believes that the Andromeda Galaxy (a member of our Local Group) is moving away from us at a slower speed than Dr. Y believes. 
C)  Dr. X believes that the universe is older than Dr. Y believes. 
D)  Dr. X believes that the universe will someday stop expanding, while Dr. Y believes it will expand forever. 
E)  Dr. X believes that the universe has a much higher density than Dr. Y believes. 
A)  Dr. X believes that the universe is expanding, but Dr. Y does not. 
B)  Dr. X believes that the Andromeda Galaxy (a member of our Local Group) is moving away from us at a slower speed than Dr. Y believes. 
C)  Dr. X believes that the universe is older than Dr. Y believes. 
D)  Dr. X believes that the universe will someday stop expanding, while Dr. Y believes it will expand forever. 
E)  Dr. X believes that the universe has a much higher density than Dr. Y believes.

Question 9

I observe a galaxy that is 100 million light years away. Which of the following do I see?

Accepted Answer

A)  the light from the galaxy as it is today, and it is blueshifted 
B)  the light from the galaxy as it is today, and it is redshifted 
C)  the light from the galaxy as it was 100 million years ago, and it is blueshifted 
D)  the light from the galaxy as it was 100 million years ago, and it is redshifted 
E)  Nothing: the galaxy lies beyond the cosmological horizon. 
A)  the light from the galaxy as it is today, and it is blueshifted 
B)  the light from the galaxy as it is today, and it is redshifted 
C)  the light from the galaxy as it was 100 million years ago, and it is blueshifted 
D)  the light from the galaxy as it was 100 million years ago, and it is redshifted 
E)  Nothing: the galaxy lies beyond the cosmological horizon.

Question 10

Which characteristic is not generally true of a starburst galaxy?

Accepted Answer

A)  The observed features that cause us to classify it as a "starburst" must be only temporary phenomena in the galaxy's history. 
B)  Its rate of star formation is many times higher than the rate of star formation in the Milky Way. 
C)  Supernovae occur so frequently that their effects combine to drive a galactic wind that blows material into intergalactic space. 
D)  The observed features of the starburst are thought to be caused by the presence of a supermassive black hole in the galaxy's center. 
A)  The observed features that cause us to classify it as a "starburst" must be only temporary phenomena in the galaxy's history. 
B)  Its rate of star formation is many times higher than the rate of star formation in the Milky Way. 
C)  Supernovae occur so frequently that their effects combine to drive a galactic wind that blows material into intergalactic space. 
D)  The observed features of the starburst are thought to be caused by the presence of a supermassive black hole in the galaxy's center.

Question 11

The disk component of a spiral galaxy includes which of the following parts?

Accepted Answer

A)  halo 
B)  bulge 
C)  spiral arms 
D)  globular clusters 
E)  all of the above 
A)  halo 
B)  bulge 
C)  spiral arms 
D)  globular clusters 
E)  all of the above

Question 12

The collision of two spiral galaxies will likely result in a single giant spiral galaxy.

Accepted Answer

A) True 
 B)False

Question 13

When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent?

Accepted Answer

A)  The inside of the balloon does not represent any part of our universe. 
B)  The center of the universe 
C)  The entire universe 
D)  Regions of the universe beyond the Milky Way Galaxy 
A)  The inside of the balloon does not represent any part of our universe. 
B)  The center of the universe 
C)  The entire universe 
D)  Regions of the universe beyond the Milky Way Galaxy

Question 14

Galaxy mergers take hundreds of millions of years to complete.

Accepted Answer

A) True 
 B)False

Question 15

What evidence suggests that the protogalactic cloud that formed the Milky Way resulted from several collisions among smaller clouds?

Accepted Answer

A)  The stars in the halo of the Milky Way are organized into several dense clusters arranged throughout the halo. 
B)  The Milky Way resembles an elliptical galaxy more than other spirals do. 
C)  Halo stars differ in age and heavy-element content, but these variations do not seem to depend on the stars' distance from the galactic center. 
D)  The bulge of the Milky Way is surrounded by many globular clusters, just as elliptical galaxies are. 
E)  The Milky Way is the central galaxy of a dense cluster of galaxies. 
A)  The stars in the halo of the Milky Way are organized into several dense clusters arranged throughout the halo. 
B)  The Milky Way resembles an elliptical galaxy more than other spirals do. 
C)  Halo stars differ in age and heavy-element content, but these variations do not seem to depend on the stars' distance from the galactic center. 
D)  The bulge of the Milky Way is surrounded by many globular clusters, just as elliptical galaxies are. 
E)  The Milky Way is the central galaxy of a dense cluster of galaxies.

Question 16

What evidence supports the idea that a collision between two spiral galaxies might lead to the formation of a single elliptical galaxy?

Accepted Answer

A)  observations of some elliptical galaxies surrounded by shells of stars that probably formed from stars stripped out of smaller galaxies 
B)  the fact that elliptical galaxies dominate the galaxy populations at the cores of dense clusters of galaxies 
C)  observations of some elliptical galaxies with stars and gas clouds in their cores that orbit differently from the other stars in the galaxy 
D)  observations of giant elliptical galaxies at the center of dense clusters that may have grown by consuming other galaxies 
E)  all of the above 
A)  observations of some elliptical galaxies surrounded by shells of stars that probably formed from stars stripped out of smaller galaxies 
B)  the fact that elliptical galaxies dominate the galaxy populations at the cores of dense clusters of galaxies 
C)  observations of some elliptical galaxies with stars and gas clouds in their cores that orbit differently from the other stars in the galaxy 
D)  observations of giant elliptical galaxies at the center of dense clusters that may have grown by consuming other galaxies 
E)  all of the above

Question 17

Cosmological redshift is the result of ________.

Accepted Answer

A)  the high speeds at which galaxies move within clusters 
B)  the expansion of the universe 
C)  very old, red stars in distant galaxies 
D)  supermassive black holes 
A)  the high speeds at which galaxies move within clusters 
B)  the expansion of the universe 
C)  very old, red stars in distant galaxies 
D)  supermassive black holes

Question 18

How are the jets produced by radio galaxies similar to those produced by protostars?

Accepted Answer

Jets in radio galaxies and in protostars

Question 19

Use the graph above showing data for the brightest galaxies in clusters of galaxies to answer the following question. You find a cluster of galaxies, but you do not know how far away it is. The brightest galaxy's infrared color is 0.65. Given the data for brightest galaxies in the graph above, your best estimate for the distance is:

Accepted Answer

A)  2.5 x 10⁹ (2.5 billion) light years. 
B)  4 x 10⁹ (4 billion) light years. 
C)  1 x 10⁹ (1 billion) light years. 
D)  It is impossible to say since there are exceptions. 
A)  2.5 x 10⁹ (2.5 billion) light years. 
B)  4 x 10⁹ (4 billion) light years. 
C)  1 x 10⁹ (1 billion) light years. 
D)  It is impossible to say since there are exceptions.

Question 20

What is a standard candle?

Accepted Answer

A)  an object for which we are likely to know its true luminosity 
B)  an object for which we can easily measure its apparent brightness 
C)  a class of objects that we know all have exactly the same luminosity 
D)  any star for which we know its exact apparent brightness 
E)  a unit of luminosity used by astronomers 
A)  an object for which we are likely to know its true luminosity 
B)  an object for which we can easily measure its apparent brightness 
C)  a class of objects that we know all have exactly the same luminosity 
D)  any star for which we know its exact apparent brightness 
E)  a unit of luminosity used by astronomers

Which of the following cannot be true of the very first stars formed in the Universe?

How was Edwin Hubble able to use his discovery of Cepheids in Andromeda to prove that the "spiral nebulae" were actually galaxies external to the Milky Way?

Spiral galaxies have more gas, dust, and young stars than elliptical galaxies.

What two observable properties of a Cepheid variable are directly related to one another?

Suppose that we look at a photograph of many galaxies. Assuming that all galaxies formed at about the same time, which galaxy in the picture is the youngest?

Why are white dwarf supernovae more useful than massive star supernovae for measuring cosmic distances?

Most active galactic nuclei are at large distances from us; relatively few nearby galaxies harbor active galactic nuclei. What does this imply?

Dr. X believes that the Hubble constant is H₀ = 20 km/s/Mly while Dr. Y believes it is H₀ = 24 km/s/Mly. Which statement below automatically follows?

I observe a galaxy that is 100 million light years away. Which of the following do I see?

Which characteristic is not generally true of a starburst galaxy?

The disk component of a spiral galaxy includes which of the following parts?

The collision of two spiral galaxies will likely result in a single giant spiral galaxy.

When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent?

Galaxy mergers take hundreds of millions of years to complete.

What evidence suggests that the protogalactic cloud that formed the Milky Way resulted from several collisions among smaller clouds?

What evidence supports the idea that a collision between two spiral galaxies might lead to the formation of a single elliptical galaxy?

Cosmological redshift is the result of ________.

How are the jets produced by radio galaxies similar to those produced by protostars?

What is a standard candle?

Our Place in 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 Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

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

Our Star

Surveying the Stars

Star Stuff

Bizarre Stellar Graveyard

Our Galaxy

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

The Beginning of Time

Life in the Universe

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Exam 15: Galaxies and the Foundation of Modern Cosmology

Which of the following cannot be true of the very first stars formed in the Universe?

How was Edwin Hubble able to use his discovery of Cepheids in Andromeda to prove that the "spiral nebulae" were actually galaxies external to the Milky Way?

Spiral galaxies have more gas, dust, and young stars than elliptical galaxies.

What two observable properties of a Cepheid variable are directly related to one another?

Suppose that we look at a photograph of many galaxies. Assuming that all galaxies formed at about the same time, which galaxy in the picture is the youngest?

Why are white dwarf supernovae more useful than massive star supernovae for measuring cosmic distances?

Most active galactic nuclei are at large distances from us; relatively few nearby galaxies harbor active galactic nuclei. What does this imply?

Dr. X believes that the Hubble constant is H₀ = 20 km/s/Mly while Dr. Y believes it is H₀ = 24 km/s/Mly. Which statement below automatically follows?

I observe a galaxy that is 100 million light years away. Which of the following do I see?

Which characteristic is not generally true of a starburst galaxy?

The disk component of a spiral galaxy includes which of the following parts?

The collision of two spiral galaxies will likely result in a single giant spiral galaxy.

When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent?

Galaxy mergers take hundreds of millions of years to complete.

What evidence suggests that the protogalactic cloud that formed the Milky Way resulted from several collisions among smaller clouds?

What evidence supports the idea that a collision between two spiral galaxies might lead to the formation of a single elliptical galaxy?

Cosmological redshift is the result of ________.

How are the jets produced by radio galaxies similar to those produced by protostars?

What is a standard candle?

Our Place in 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 Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

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

Our Star

Surveying the Stars

Star Stuff

Bizarre Stellar Graveyard

Our Galaxy

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

The Beginning of Time

Life in the Universe

Filters