Question 1

Why do we believe there is dark matter?

Accepted Answer

When we use the Keplerian equation to determine the mass of the Galaxy we find a value of 100 billion Suns inside the Sun's orbital radius, or about 200 billion Suns all the way out to the end of the visible part of the spiral arms and halo stars. However, when we look the rotation curve we find objects distant from the center rotating much faster than expected. To account for this, there must be significantly more mass outside the visible portion of our Galaxy that we cannot see.

Question 2

Most of the new star formation in the Galaxy is found in the

Accepted Answer

A)  halo. 
B)  spiral arms. 
C)  bulge. 
D)  Galactic center. 
E)  globular clusters. 
A)  halo. 
B)  spiral arms. 
C)  bulge. 
D)  Galactic center. 
E)  globular clusters. B

Question 3

A pulsating variable star with a period of 10 days would be a Cepheid.

Accepted Answer

A) True 
 B)False  True

Question 4

Most of the mass of the Milky Way seems to exist in the form of

Accepted Answer

A)  young stars in the disk. 
B)  old stars in the Galactic halo. 
C)  hydrogen gas in the disk and spiral arms. 
D)  dark matter out in the Galactic halo. 
E)  the black hole in the Galactic center. 
A)  young stars in the disk. 
B)  old stars in the Galactic halo. 
C)  hydrogen gas in the disk and spiral arms. 
D)  dark matter out in the Galactic halo. 
E)  the black hole in the Galactic center.

Question 5

It is harder to map the structure of the Milky Way as a whole in visible light than with any other form of electromagnetic radiation.

Accepted Answer

A) True 
 B)False

Question 6

What is the evidence to support the existence of a black hole at the center of the Milky Way?

Accepted Answer

A large amount of activity is present. T

Question 7

The radio source ________ is located in a place consistent with the center of our Galaxy.

Accepted Answer

A)  Cygnus X-1 
B)  3C 273 
C)  47 Tucanae 
D)  M-8, the Lagoon Nebula 
E)  Sgr A* 
A)  Cygnus X-1 
B)  3C 273 
C)  47 Tucanae 
D)  M-8, the Lagoon Nebula 
E)  Sgr A*

Question 8

The period-luminosity relation is critical in finding distances with

Accepted Answer

A)  RR Lyrae stars. 
B)  trigonometric parallaxes. 
C)  spectroscopic parallaxes. 
D)  Cepheid variables. 
E)  pulsars. 
A)  RR Lyrae stars. 
B)  trigonometric parallaxes. 
C)  spectroscopic parallaxes. 
D)  Cepheid variables. 
E)  pulsars.

Question 9

Spiral arms are thought to be sites of ________, based on the observations newly formed stars and interstellar dust lanes in and around these features.

Accepted Answer

The answer of Spiral arms are thought to be sites...

Question 10

The Earth lies close to the center of the Galaxy.

Accepted Answer

A) True 
 B)False

Question 11

How can Kepler's Third Law be used to estimate the mass of the galaxy?

Accepted Answer

We can find the total mass interior to a

Question 12

Why is visible light a bad choice for studying the core of the Galaxy? What is better?

Accepted Answer

Dust in the Galactic plane blocks our vi

Question 13

Why were globular clusters so vital to Harlow Shapley's success?

Accepted Answer

Globular clusters lie in the h

Question 14

The "aspect ratio" of thickness to width of the Galactic disk is about

Accepted Answer

A)  1:2. 
B)  1:5. 
C)  1:10. 
D)  1:100. 
E)  1:1,000. 
A)  1:2. 
B)  1:5. 
C)  1:10. 
D)  1:100. 
E)  1:1,000.

Question 15

It was the distribution of ________ that showed Harlow Shapley we were nowhere near the center of the Milky Way early in the 20th century.

Accepted Answer

A)  planetary nebulae 
B)  emission nebulae 
C)  open clusters 
D)  globular clusters 
E)  supernova remnants 
A)  planetary nebulae 
B)  emission nebulae 
C)  open clusters 
D)  globular clusters 
E)  supernova remnants

Question 16

How does content of elements heavier than helium vary between young and old stars? Why?

Accepted Answer

Older stars are made of almost

Question 17

What two observations allow us to calculate the Galaxy's mass?

Accepted Answer

A)  The Sun's mass and velocity in orbit of the Galactic center 
B)  The Sun's age and period of the Galactic Year 
C)  The Sun's orbital velocity and its distance from the Galactic center 
D)  The Sun's mass and its age 
E)  The Sun's composition and luminosity 
A)  The Sun's mass and velocity in orbit of the Galactic center 
B)  The Sun's age and period of the Galactic Year 
C)  The Sun's orbital velocity and its distance from the Galactic center 
D)  The Sun's mass and its age 
E)  The Sun's composition and luminosity

Question 18

Describe our location in the Milky Way.

Accepted Answer

We lie in a spiral arm about 2

Question 19

How old is the Galaxy? How do we know this?

Accepted Answer

The H-R diagrams of the globular cluster

Question 20

Detailed measurements of the disk and central bulge region of our Galaxy suggest our Milky Way is a

Accepted Answer

A)  dwarf galaxy. 
B)  spiral galaxy. 
C)  very flat elliptical galaxy. 
D)  very dusty irregular galaxy. 
E)  quasar. 
A)  dwarf galaxy. 
B)  spiral galaxy. 
C)  very flat elliptical galaxy. 
D)  very dusty irregular galaxy. 
E)  quasar.

Why do we believe there is dark matter?

Most of the new star formation in the Galaxy is found in the

A pulsating variable star with a period of 10 days would be a Cepheid.

Most of the mass of the Milky Way seems to exist in the form of

It is harder to map the structure of the Milky Way as a whole in visible light than with any other form of electromagnetic radiation.

What is the evidence to support the existence of a black hole at the center of the Milky Way?

The radio source ________ is located in a place consistent with the center of our Galaxy.

The period-luminosity relation is critical in finding distances with

Spiral arms are thought to be sites of ________, based on the observations newly formed stars and interstellar dust lanes in and around these features.

The Earth lies close to the center of the Galaxy.

How can Kepler's Third Law be used to estimate the mass of the galaxy?

Why is visible light a bad choice for studying the core of the Galaxy? What is better?

Why were globular clusters so vital to Harlow Shapley's success?

The "aspect ratio" of thickness to width of the Galactic disk is about

It was the distribution of ________ that showed Harlow Shapley we were nowhere near the center of the Milky Way early in the 20th century.

How does content of elements heavier than helium vary between young and old stars? Why?

What two observations allow us to calculate the Galaxy's mass?

Describe our location in the Milky Way.

How old is the Galaxy? How do we know this?

Detailed measurements of the disk and central bulge region of our Galaxy suggest our Milky Way is a

The Night Sky

Light and Telescopes

The Solar System

Earth and Its Moon

The Eight Planets

Small Bodies in the Solar System

Formation of Planetary Systems

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Measuring the Stars

Star Formation and Evolution

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Galaxies

Cosmology and the Universe

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Exam 13: The Milky Way Galaxy

Why do we believe there is dark matter?

Most of the new star formation in the Galaxy is found in the

A pulsating variable star with a period of 10 days would be a Cepheid.

Most of the mass of the Milky Way seems to exist in the form of

It is harder to map the structure of the Milky Way as a whole in visible light than with any other form of electromagnetic radiation.

What is the evidence to support the existence of a black hole at the center of the Milky Way?

The radio source ________ is located in a place consistent with the center of our Galaxy.

The period-luminosity relation is critical in finding distances with

Spiral arms are thought to be sites of ________, based on the observations newly formed stars and interstellar dust lanes in and around these features.

The Earth lies close to the center of the Galaxy.

How can Kepler's Third Law be used to estimate the mass of the galaxy?

Why is visible light a bad choice for studying the core of the Galaxy? What is better?

Why were globular clusters so vital to Harlow Shapley's success?

The "aspect ratio" of thickness to width of the Galactic disk is about

It was the distribution of ________ that showed Harlow Shapley we were nowhere near the center of the Milky Way early in the 20th century.

How does content of elements heavier than helium vary between young and old stars? Why?

What two observations allow us to calculate the Galaxy's mass?

Describe our location in the Milky Way.

How old is the Galaxy? How do we know this?

Detailed measurements of the disk and central bulge region of our Galaxy suggest our Milky Way is a

The Night Sky

Light and Telescopes

The Solar System

Earth and Its Moon

The Eight Planets

Small Bodies in the Solar System

Formation of Planetary Systems

The Sun

Measuring the Stars

Star Formation and Evolution

Stellar Explosions

Black Holes

Galaxies

Cosmology and the Universe

Filters