Question 1

The primary way that we observe the atomic hydrogen that makes up most of the interstellar gas in the Milky Way is with ________.

Accepted Answer

A)  radio telescopes observing at a wavelength of 21 centimeters 
B)  ground-based visible-light telescopes 
C)  space-based ultraviolet telescopes 
D)  X-ray telescopes 
A)  radio telescopes observing at a wavelength of 21 centimeters 
B)  ground-based visible-light telescopes 
C)  space-based ultraviolet telescopes 
D)  X-ray telescopes

Question 2

Which of the following properties is more likely to be a characteristic of a halo star in the Milky Way, not a disk star?

Accepted Answer

A)  It orbits the center of the Milky Way galaxy. 
B)  It has a low ratio of iron to hydrogen. 
C)  It could be quite young. 
D)  It is moving very slowly relative to the Sun's motion. 
A)  It orbits the center of the Milky Way galaxy. 
B)  It has a low ratio of iron to hydrogen. 
C)  It could be quite young. 
D)  It is moving very slowly relative to the Sun's motion.

Question 3

Open clusters and young stars are generally found only in the disk of the Milky Way and not in the halo.

Accepted Answer

A) True 
 B)False

Question 4

Spiral arms appear bright because ________.

Accepted Answer

A)  they contain more hot young stars than other parts of the disk 
B)  they contain far more stars than other parts of the galactic disk 
C)  they contain more molecular clouds than other parts of the disk 
D)  they are the only places where we find stars within the disk of the galaxy 
A)  they contain more hot young stars than other parts of the disk 
B)  they contain far more stars than other parts of the galactic disk 
C)  they contain more molecular clouds than other parts of the disk 
D)  they are the only places where we find stars within the disk of the galaxy

Question 5

How are interstellar bubbles made?

Accepted Answer

A)  by the collapse of a gas cloud to form stars 
B)  by the ejection of planetary nebulae from low-mass stars 
C)  by the winds of massive stars and supernovae explosions 
D)  by collisions between the Milky Way and satellite dwarf galaxies 
E)  by the rapidly rotating magnetic fields of pulsars 
A)  by the collapse of a gas cloud to form stars 
B)  by the ejection of planetary nebulae from low-mass stars 
C)  by the winds of massive stars and supernovae explosions 
D)  by collisions between the Milky Way and satellite dwarf galaxies 
E)  by the rapidly rotating magnetic fields of pulsars

Question 6

What is the most abundant molecule in interstellar clouds besides molecular hydrogen?

Accepted Answer

A)  molecular helium 
B)  water 
C)  carbon monoxide 
D)  ammonia 
E)  methane 
A)  molecular helium 
B)  water 
C)  carbon monoxide 
D)  ammonia 
E)  methane

Question 7

How should we expect the Milky Way's interstellar medium to be different in 50 billion years than it is today?

Accepted Answer

A)  The total amount of gas will be much less than it is today. 
B)  The total amount of gas will be about the same, but the percentage of elements heavier than hydrogen and helium will have risen from the current 2% to more than 50%. 
C)  The total amount of gas will be much greater, since many stars will undergo supernovae between now and then. 
D)  Thanks to the recycling of the star-gas-star cycle, the interstellar medium should look about the same in 50 billion years as it does today. 
A)  The total amount of gas will be much less than it is today. 
B)  The total amount of gas will be about the same, but the percentage of elements heavier than hydrogen and helium will have risen from the current 2% to more than 50%. 
C)  The total amount of gas will be much greater, since many stars will undergo supernovae between now and then. 
D)  Thanks to the recycling of the star-gas-star cycle, the interstellar medium should look about the same in 50 billion years as it does today.

Question 8

Which of the following stars would be most likely to have the same abundance of elements heavier than helium as a red main sequence star in globular cluster M13?

Accepted Answer

A)  None of these choices 
B)  Red giant in globular cluster M13 
C)  A red main sequence star in the disk of the Milky Way 
A)  None of these choices 
B)  Red giant in globular cluster M13 
C)  A red main sequence star in the disk of the Milky Way

Question 9

Briefly explain why stars that formed early in the history of the galaxy contain a smaller proportion of heavy elements than stars that formed more recently.

Accepted Answer

The star-gas-star cycle gradually enrich

Question 10

All the following types of objects are found almost exclusively in the disk (rather than the halo) of the Milky Way except ________.

Accepted Answer

A)  globular clusters 
B)  young stars 
C)  X-ray binaries 
D)  high-mass, red supergiant stars 
A)  globular clusters 
B)  young stars 
C)  X-ray binaries 
D)  high-mass, red supergiant stars

Question 11

Where does most star formation occur in the Milky Way today?

Accepted Answer

A)  in the halo 
B)  in the bulge 
C)  in the spiral arms 
D)  in the Galactic center 
E)  uniformly throughout the Galaxy 
A)  in the halo 
B)  in the bulge 
C)  in the spiral arms 
D)  in the Galactic center 
E)  uniformly throughout the Galaxy

Question 12

Why do spiral arms have a blue color?

Accepted Answer

Spiral arms are waves of enhanced densit

The primary way that we observe the atomic hydrogen that makes up most of the interstellar gas in the Milky Way is with ________.

Which of the following properties is more likely to be a characteristic of a halo star in the Milky Way, not a disk star?

Open clusters and young stars are generally found only in the disk of the Milky Way and not in the halo.

Spiral arms appear bright because ________.

How are interstellar bubbles made?

What is the most abundant molecule in interstellar clouds besides molecular hydrogen?

How should we expect the Milky Way's interstellar medium to be different in 50 billion years than it is today?

Which of the following stars would be most likely to have the same abundance of elements heavier than helium as a red main sequence star in globular cluster M13?

Briefly explain why stars that formed early in the history of the galaxy contain a smaller proportion of heavy elements than stars that formed more recently.

All the following types of objects are found almost exclusively in the disk (rather than the halo) of the Milky Way except ________.

Where does most star formation occur in the Milky Way today?

Why do spiral arms have a blue color?

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

Galaxies and the Foundation of Modern Cosmology

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

The Beginning of Time

Life in the Universe

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Exam 14: Our Galaxy

The primary way that we observe the atomic hydrogen that makes up most of the interstellar gas in the Milky Way is with ________.

Which of the following properties is more likely to be a characteristic of a halo star in the Milky Way, not a disk star?

Open clusters and young stars are generally found only in the disk of the Milky Way and not in the halo.

Spiral arms appear bright because ________.

How are interstellar bubbles made?

What is the most abundant molecule in interstellar clouds besides molecular hydrogen?

How should we expect the Milky Way's interstellar medium to be different in 50 billion years than it is today?

Which of the following stars would be most likely to have the same abundance of elements heavier than helium as a red main sequence star in globular cluster M13?

Briefly explain why stars that formed early in the history of the galaxy contain a smaller proportion of heavy elements than stars that formed more recently.

All the following types of objects are found almost exclusively in the disk (rather than the halo) of the Milky Way except ________.

Where does most star formation occur in the Milky Way today?

Why do spiral arms have a blue color?

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

Galaxies and the Foundation of Modern Cosmology

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

The Beginning of Time

Life in the Universe

Filters