Question 1

" Spurs" are probably the result of ____.

Accepted Answer

A)  self-sustaining star formation 
B)  spiral density waves 
C)  differential rotation 
D)  the central galactic bar 
E)  the short lifetime of O stars 
A)  self-sustaining star formation 
B)  spiral density waves 
C)  differential rotation 
D)  the central galactic bar 
E)  the short lifetime of O stars

Question 2

Stars at different distances from the galactic center revolve with different periods, an effect called _______________ rotation.

Accepted Answer

The answer of Stars at different distances from the galactic...

Question 3

Globular clusters are used as spiral tracers.

Accepted Answer

A) True 
 B)False

Question 4

Almost all of the gas and dust in the Milky Way is located in the ____.

Accepted Answer

A)  halo 
B)  central bulge 
C)  disk 
D)  corona 
E)  center 
A)  halo 
B)  central bulge 
C)  disk 
D)  corona 
E)  center

Question 5

Why was it difficult for astronomers to develop a clear understanding of the Milky Way until the last few decades?

Accepted Answer

Interstellar dust obscures most of the l

Question 6

One of the most important features that must be explained by models during the formation of the galaxy is the ____.

Accepted Answer

A)  formation of spiral arms 
B)  differences in age and metallicity of stars, especially in the halo 
C)  formation of the central supermassive black hole 
D)  accumulation of dark matter in the corona 
E)  importance of spiral arms to star formation 
A)  formation of spiral arms 
B)  differences in age and metallicity of stars, especially in the halo 
C)  formation of the central supermassive black hole 
D)  accumulation of dark matter in the corona 
E)  importance of spiral arms to star formation

Question 7

A group of one hundred to a few thousand stars in a region of 25 pc in diameter that were created at the same time and our bound together by gravity is called a(n) ____.

Accepted Answer

A)  associated cluster 
B)  open cluster 
C)  closed cluster 
D)  globular cluster 
E)  nebular cluster 
A)  associated cluster 
B)  open cluster 
C)  closed cluster 
D)  globular cluster 
E)  nebular cluster

Question 8

Elements above hydrogen and helium come from _____.

Accepted Answer

A)  the early stages of the Universe, before the formation of stars and galaxies 
B)  the collision of neutron stars and black holes 
C)  cooling and accretion of molecules in dense molecular clouds 
D)  the last phases of stellar evolution and stellar "death" 
E)  matter falling into supermassive black holes 
A)  the early stages of the Universe, before the formation of stars and galaxies 
B)  the collision of neutron stars and black holes 
C)  cooling and accretion of molecules in dense molecular clouds 
D)  the last phases of stellar evolution and stellar "death" 
E)  matter falling into supermassive black holes

Question 9

Explain the reasoning that leads astronomers to believe that our galaxy is surrounded by a cloud of "dark matter".

Accepted Answer

Stars rotate around the galactic center

Question 10

The mass of the Milky Way galaxy is a few ____.

Accepted Answer

A)  million solar masses 
B)  hundreds of millions of solar masses 
C)  billion solar masses 
D)  hundreds of billions of solar masses 
E)  trillion solar masses 
A)  million solar masses 
B)  hundreds of millions of solar masses 
C)  billion solar masses 
D)  hundreds of billions of solar masses 
E)  trillion solar masses

Question 11

What is the monolithic collapse hypothesis unable to explain?

Accepted Answer

A)  The randomly oriented, elongated orbits of stars in the bulge and halo 
B)  The circular motion of stars in the galactic disk 
C)  The difference in metallicity between the spherical component and the disk component of the galaxy 
D)  The elongated bar shape of the central bulge 
E)  The low density of material in the halo, compared to the central bulge 
A)  The randomly oriented, elongated orbits of stars in the bulge and halo 
B)  The circular motion of stars in the galactic disk 
C)  The difference in metallicity between the spherical component and the disk component of the galaxy 
D)  The elongated bar shape of the central bulge 
E)  The low density of material in the halo, compared to the central bulge

Question 12

The black hole at the center of our galaxy is too large to be the remnant of a single star.

Accepted Answer

A) True 
 B)False

Question 13

Objects used to map spiral arms are called spiral _______________.

Accepted Answer

The answer of Objects used to map spiral arms are...

Question 14

What observed feature of the Milky Way is better explained by the bottom-up hypothesis of galactic formation, as opposed to the monolithic collapse model?

Accepted Answer

A)  The elongated shape of the central bulge of the galaxy 
B)  The different metallicities of the bulge and disk of the galaxy 
C)  The difference in age of globular clusters 
D)  The supermassive black hole found at center of the galaxy 
E)  The very little gas or dust that halo contains 
A)  The elongated shape of the central bulge of the galaxy 
B)  The different metallicities of the bulge and disk of the galaxy 
C)  The difference in age of globular clusters 
D)  The supermassive black hole found at center of the galaxy 
E)  The very little gas or dust that halo contains

Question 15

Why do stars in the central bulge have a lower metallicity than stars in the disk?

Accepted Answer

Stars in the central bulge formed first,

Question 16

Astronomers refer to elements heavier than helium as _______________.

Accepted Answer

The answer of Astronomers refer to elements heavier than helium...

Question 17

Figure 12-14(for the following questions)
The accompanying graph above clearly shows that ____.

Accepted Answer

A)  Type I Cepheid variables are always brighter than Type II Cepheids 
B)  Type II Cepheid variables always have shorter pulsation periods than Type I Cepheids 
C)  Type I Cepheids are always more distant than Type II Cepheids 
D)  RR Lyrae stars can have longer pulsation periods than Cepheid variables 
E)  RR Lyrae stars are always dimmer than Cepheid variables. 
A)  Type I Cepheid variables are always brighter than Type II Cepheids 
B)  Type II Cepheid variables always have shorter pulsation periods than Type I Cepheids 
C)  Type I Cepheids are always more distant than Type II Cepheids 
D)  RR Lyrae stars can have longer pulsation periods than Cepheid variables 
E)  RR Lyrae stars are always dimmer than Cepheid variables.

Question 18

William and Caroline Herschel attempted to make a map of the Milky Way galaxy by counting the number of stars visible in different directions.

Accepted Answer

A) True 
 B)False

Question 19

O stars must be formed in spiral arms because _____.

Accepted Answer

A)  they do not live long enough to move out of the arm 
B)  the dust clouds they form from are only found there 
C)  all stars are formed in spiral arms 
D)  they are only found in spiral arms their gravitational forces takes them to that location 
E)  they are left behind and found in the region behind the spiral arm 
A)  they do not live long enough to move out of the arm 
B)  the dust clouds they form from are only found there 
C)  all stars are formed in spiral arms 
D)  they are only found in spiral arms their gravitational forces takes them to that location 
E)  they are left behind and found in the region behind the spiral arm

Question 20

Figure 12-14(for the following questions)
Examine the accompanying graph. Harlow Shapley did not know that there are two categories of Cepheid variables; he was only familiar with those such as d Cepheii. Because of this, some of the Cepheid variables he observed ____.

Accepted Answer

A)  were dimmer than he expected 
B)  were brighter than he expected 
C)  had a longer pulsation period than he expected 
D)  had a shorter pulsation period than he expected 
E)  were RR Lyrae variables 
A)  were dimmer than he expected 
B)  were brighter than he expected 
C)  had a longer pulsation period than he expected 
D)  had a shorter pulsation period than he expected 
E)  were RR Lyrae variables

Exam 15: The Milky Way Galaxy

" Spurs" are probably the result of ____.

Stars at different distances from the galactic center revolve with different periods, an effect called _______________ rotation.

Globular clusters are used as spiral tracers.

Almost all of the gas and dust in the Milky Way is located in the ____.

Why was it difficult for astronomers to develop a clear understanding of the Milky Way until the last few decades?

One of the most important features that must be explained by models during the formation of the galaxy is the ____.

A group of one hundred to a few thousand stars in a region of 25 pc in diameter that were created at the same time and our bound together by gravity is called a(n) ____.

Elements above hydrogen and helium come from _____.

Explain the reasoning that leads astronomers to believe that our galaxy is surrounded by a cloud of "dark matter".

The mass of the Milky Way galaxy is a few ____.

What is the monolithic collapse hypothesis unable to explain?

The black hole at the center of our galaxy is too large to be the remnant of a single star.

Objects used to map spiral arms are called spiral _______________.

What observed feature of the Milky Way is better explained by the bottom-up hypothesis of galactic formation, as opposed to the monolithic collapse model?

Why do stars in the central bulge have a lower metallicity than stars in the disk?

Astronomers refer to elements heavier than helium as _______________.

Figure 12-14(for the following questions) The accompanying graph above clearly shows that ____.

William and Caroline Herschel attempted to make a map of the Milky Way galaxy by counting the number of stars visible in different directions.

O stars must be formed in spiral arms because _____.

Figure 12-14(for the following questions) Examine the accompanying graph. Harlow Shapley did not know that there are two categories of Cepheid variables; he was only familiar with those such as d Cepheii. Because of this, some of the Cepheid variables he observed ____.

Here and Now

A Users Guide to the Sky

Moon Phases and Eclipses

Origins of Modern Astronomy

Gravity

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Interstellar Medium

Formation and Structure of Stars

Stellar Evolution

Deaths of Stars

Neutron Stars and Black Holes

Galaxies

Supermassive Black Holes and Active Galaxies

Modern Cosmology

Origin of the Solar System and Extrasolar Planets

Earth the Active Planet

The Moon and Mercury

Venus and Mars

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Uranus Neptune Pluto and the Kuiper Belt

Meteorites Asteroids and Comets

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