Question 1

Which objects in our Milky Way galaxy have orbits that are NOT similar to stars in elliptical galaxies?

Accepted Answer

A)  disk stars 
B)  halo stars 
C)  bulge stars 
D)  globular clusters 
E)  satellite dwarf galaxies 
A)  disk stars 
B)  halo stars 
C)  bulge stars 
D)  globular clusters 
E)  satellite dwarf galaxies

Question 2

The location and motions of interstellar gas can be strongly affected by what?

Accepted Answer

A)  Dark matter 
B)  Low-mass stars 
C)  Pulsars 
D)  Supernovae 
E)  Halo stars 
A)  Dark matter 
B)  Low-mass stars 
C)  Pulsars 
D)  Supernovae 
E)  Halo stars

Question 3

Suppose it was discovered that the galaxy has constantly been absorbing large amounts of gas that never had any stars form in it. Would this complicate our interpretation of ages and chemical enrichment?

Accepted Answer

Such a discovery might indeed complicate

Question 4

By comparing globular clusters, you find that Cluster A's RR Lyrae stars are 100 times fainter than Cluster B's RR Lyrae stars. You know that both clusters have approximately the same chemical composition and age, and thus their RR Lyrae stars should have the same luminosities. Which is true about the clusters' distances?

Accepted Answer

A)  Cluster A is 10 times farther away than Cluster B. 
B)  Cluster A is 10 times closer to us than Cluster B. 
C)  Clusters A and B are approximately the same distances from us. 
D)  Cluster A is 100 times farther away than Cluster B. 
E)  Cluster A is 100 times closer to us than Cluster B. 
A)  Cluster A is 10 times farther away than Cluster B. 
B)  Cluster A is 10 times closer to us than Cluster B. 
C)  Clusters A and B are approximately the same distances from us. 
D)  Cluster A is 100 times farther away than Cluster B. 
E)  Cluster A is 100 times closer to us than Cluster B.

Question 5

The Milky Way is like most other galaxies in that its mass is dominated by dark matter.

Accepted Answer

A) True 
 B)False

Question 6

Most of the gravity that the Sun feels in the galaxy is caused by the black hole at the center of the Milky Way.

Accepted Answer

A) True 
 B)False

Question 7

On average, we expect that __________ stars have the __________ percentage of heavy elements.

Accepted Answer

A)  older; highest 
B)  disk; lowest 
C)  bulge; lowest 
D)  halo; highest 
E)  younger; highest 
A)  older; highest 
B)  disk; lowest 
C)  bulge; lowest 
D)  halo; highest 
E)  younger; highest

Question 8

Because of the ages of globular clusters in the Milky Way, we think our galaxy's early formation history was characterized by:

Accepted Answer

A)  one single cloud of gas gently collapsing and star formation proceeding slowly within it 
B)  one single cloud of gas that rapidly collapsed and turned most of its gas into stars 
C)  violent merging of protogalactic fragments that stimulated a high rate of star formation 
D)  slow merging of protogalactic fragments after they had already turned most of their gas into stars 
E)  merging of two galaxies, each about half as massive as the Milky Way is today 
A)  one single cloud of gas gently collapsing and star formation proceeding slowly within it 
B)  one single cloud of gas that rapidly collapsed and turned most of its gas into stars 
C)  violent merging of protogalactic fragments that stimulated a high rate of star formation 
D)  slow merging of protogalactic fragments after they had already turned most of their gas into stars 
E)  merging of two galaxies, each about half as massive as the Milky Way is today

Question 9

If a globular cluster were 1,000 pc away from us and an RR Lyrae star in it had an absolute magnitude of 0.5, what would its apparent magnitude be?

Accepted Answer

A)  4.0 
B)  6.5 
C)  8.0 
D)  10.5 
E)  15.5 
A)  4.0 
B)  6.5 
C)  8.0 
D)  10.5 
E)  15.5

Question 10

What is ripping apart the Sagittarius dwarf spheroidal galaxy?

Accepted Answer

A)  a supermassive black hole at the center of the dwarf galaxy 
B)  pressure from its passage through the dark matter in the Milky Way 
C)  a violent episode of star formation 
D)  the gravitational tidal force of the Milky Way 
E)  supernova explosions occurring in the dwarf galaxy 
A)  a supermassive black hole at the center of the dwarf galaxy 
B)  pressure from its passage through the dark matter in the Milky Way 
C)  a violent episode of star formation 
D)  the gravitational tidal force of the Milky Way 
E)  supernova explosions occurring in the dwarf galaxy

Question 11

The Milky Way has two major spiral arms that emanate from the ends of its bar.

Accepted Answer

A) True 
 B)False

Question 12

Below are two images of the Milky Way at different wavelengths. Which one was taken at infrared wavelengths, and why do you think so?

Accepted Answer

A)  A; there are many cool stars in the image, which emit a lot of infrared light. 
B)  A; the dust in the galaxy mainly blocks infrared light and lets visible light through. 
C)  B; we see mainly warm dust emitting thermal radiation. 
D)  B; infrared light passes through the dust so we can see the galaxy's structure more clearly. 
E)  B; stars in the central bulge shine only at infrared wavelengths. 
A)  A; there are many cool stars in the image, which emit a lot of infrared light. 
B)  A; the dust in the galaxy mainly blocks infrared light and lets visible light through. 
C)  B; we see mainly warm dust emitting thermal radiation. 
D)  B; infrared light passes through the dust so we can see the galaxy's structure more clearly. 
E)  B; stars in the central bulge shine only at infrared wavelengths.

Question 13

Describe the basic scenario that describes the formation and evolution of the Milky Way, including a description of how the halo and disk formed.

Accepted Answer

Several protogalactic fragments began fo

Question 14

Globular clusters, when compared to open clusters, generally:

Accepted Answer

A)  are located closer to the center of the Milky Way 
B)  are younger in age 
C)  have fewer amounts of heavy elements 
D)  are less massive 
E)  contain more dark matter 
A)  are located closer to the center of the Milky Way 
B)  are younger in age 
C)  have fewer amounts of heavy elements 
D)  are less massive 
E)  contain more dark matter

Question 15

In a star that has a chemical abundance similar to the Sun, what percentage of its mass is made of heavy elements?

Accepted Answer

A)  0.1 percent 
B)  0.2 percent 
C)  2 percent 
D)  10 percent 
E)  20 percent 
A)  0.1 percent 
B)  0.2 percent 
C)  2 percent 
D)  10 percent 
E)  20 percent

Question 16

By comparing globular clusters, you find that Cluster A's RR Lyrae stars are 225 times fainter than Cluster B's RR Lyrae stars. You know that both clusters have approximately the same chemical composition and age, and thus their RR Lyrae stars should have the same luminosities. Which cluster has the larger distance, and what is the ratio of the clusters' distances?

Accepted Answer

Distance is given by @#IMG-DLM& , where

Question 17

Most of the mass in our galaxy is in the form of:

Accepted Answer

A)  stars 
B)  gas 
C)  dust 
D)  dark matter 
E)  globular clusters 
A)  stars 
B)  gas 
C)  dust 
D)  dark matter 
E)  globular clusters

Question 18

Halo stars formed before the Milky Way developed a thin stellar disk.

Accepted Answer

A) True 
 B)False

Question 19

Where would we find the stars with the richest abundance of massive elements? Where would we find those with the smallest amounts of massive elements? Why?

Accepted Answer

Stars with the highest abundance of mass

Question 20

The Milky Way is classified as an __________ galaxy.

Accepted Answer

A)  Sa 
B)  SBbc 
C)  Sd 
D)  SBc 
E)  SBd 
A)  Sa 
B)  SBbc 
C)  Sd 
D)  SBc 
E)  SBd

Exam 21: The Milky Waya Normal Spiral Galaxy

Which objects in our Milky Way galaxy have orbits that are NOT similar to stars in elliptical galaxies?

The location and motions of interstellar gas can be strongly affected by what?

Suppose it was discovered that the galaxy has constantly been absorbing large amounts of gas that never had any stars form in it. Would this complicate our interpretation of ages and chemical enrichment?

The Milky Way is like most other galaxies in that its mass is dominated by dark matter.

Most of the gravity that the Sun feels in the galaxy is caused by the black hole at the center of the Milky Way.

On average, we expect that __________ stars have the __________ percentage of heavy elements.

Because of the ages of globular clusters in the Milky Way, we think our galaxy's early formation history was characterized by:

If a globular cluster were 1,000 pc away from us and an RR Lyrae star in it had an absolute magnitude of 0.5, what would its apparent magnitude be?

What is ripping apart the Sagittarius dwarf spheroidal galaxy?

The Milky Way has two major spiral arms that emanate from the ends of its bar.

Below are two images of the Milky Way at different wavelengths. Which one was taken at infrared wavelengths, and why do you think so?

Describe the basic scenario that describes the formation and evolution of the Milky Way, including a description of how the halo and disk formed.

Globular clusters, when compared to open clusters, generally:

In a star that has a chemical abundance similar to the Sun, what percentage of its mass is made of heavy elements?

Most of the mass in our galaxy is in the form of:

Halo stars formed before the Milky Way developed a thin stellar disk.

Where would we find the stars with the richest abundance of massive elements? Where would we find those with the smallest amounts of massive elements? Why?

The Milky Way is classified as an __________ galaxy.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters

On average, we expect that stars have the percentage of heavy elements.