Question 1

The first attempt to map the Galaxy via star counts was done by:

Accepted Answer

A) Galileo in 1612. 
B) William Herschel in the late eighteenth century. 
C) Edward Barnard with long exposure photos about 1900. 
D) Harlow Shapley with the RR Lyrae variables in 1920. 
E) Edwin Hubble with the new 100" Mt. Wilson telescope in the 1930s. 
A) Galileo in 1612. 
B) William Herschel in the late eighteenth century. 
C) Edward Barnard with long exposure photos about 1900. 
D) Harlow Shapley with the RR Lyrae variables in 1920. 
E) Edwin Hubble with the new 100" Mt. Wilson telescope in the 1930s.

Question 2

Shapley correctly argued that the rotation of the spiral nebulae proved they could not be verydistant.

Accepted Answer

A) True 
 B)False

Question 3

In age, Population I stars are typically much ________ than those of Population II.

Accepted Answer

The answer of In age, Population I stars are typically...

Question 4

Spiral arms are regions of star formation, which accounts for their blue color.

Accepted Answer

A) True 
 B)False

Question 5

What use are 21 cm radio waves to galactic astronomers?

Accepted Answer

A) They cut through the dusty cocoons to let us watch star birth. 
B) We can reflect them off the core of the Galaxy. 
C) Their Doppler shifts let us map the motions and locations of gas in the spiral arms. 
D) They bounce off stars like our Sun to let us precisely measure their distances. 
E) They pick up the cool, dark matter much better than can optical telescopes. 
A) They cut through the dusty cocoons to let us watch star birth. 
B) We can reflect them off the core of the Galaxy. 
C) Their Doppler shifts let us map the motions and locations of gas in the spiral arms. 
D) They bounce off stars like our Sun to let us precisely measure their distances. 
E) They pick up the cool, dark matter much better than can optical telescopes.

Question 6

Density waves may explain:

Accepted Answer

A) the lack of blue stars in the Galactic halo. 
B) the random orbits of Galactic halo stars. 
C) the density of red stars in the Galactic bulge. 
D) the spiral arm structure of the Galaxy. 
E) the large number of open clusters in the Galactic halo. 
A) the lack of blue stars in the Galactic halo. 
B) the random orbits of Galactic halo stars. 
C) the density of red stars in the Galactic bulge. 
D) the spiral arm structure of the Galaxy. 
E) the large number of open clusters in the Galactic halo.

Question 7

These objects are no longer considered a good explanation for the dark matter in the Galactichalo.

Accepted Answer

A) WIMPs 
B) MACHOs 
C) black holes 
D) clouds of cool, neutral hydrogen 
E) brown dwarfs 
A) WIMPs 
B) MACHOs 
C) black holes 
D) clouds of cool, neutral hydrogen 
E) brown dwarfs

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

The region on the H-R diagram where pulsating variables occur is called the:

Accepted Answer

A) period-luminosity relation. 
B) mass-luminosity relation. 
C) instability strip. 
D) horizontal branch. 
E) main sequence appendix. 
A) period-luminosity relation. 
B) mass-luminosity relation. 
C) instability strip. 
D) horizontal branch. 
E) main sequence appendix.

Question 10

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

Accepted Answer

The H-R diagrams of the globular cluster

Question 11

Of what is the Galactic halo presumed to be composed? What evidence supports thisconclusion?

Accepted Answer

The globular clusters are most obvious,

Question 12

The majority of the mass of the Milky Way lies farther out than the Sun's orbit.

Accepted Answer

A) True 
 B)False

Question 13

The interstellar ________ absorbs light from stars and makes them appear fainter and redderthan they otherwise would appear.

Accepted Answer

The answer of The interstellar ________ absorbs light from stars...

Question 14

From Earth, the view of the Milky Way is a thin band of stars across the night sky. The partof the Milky Way Galaxy that is described here is the:

Accepted Answer

A) Galactic bulge. 
B) spiral arm. 
C) Galactic disk. 
D) Galactic halo. 
E) globular cluster. 
A) Galactic bulge. 
B) spiral arm. 
C) Galactic disk. 
D) Galactic halo. 
E) globular cluster.

Question 15

For what type of object is the period-luminosity relation used for determining distances?

Accepted Answer

A) RR Lyrae variables 
B) T Tauri variables 
C) Cepheids 
D) cataclysmic variables 
E) planetary nebulae 
A) RR Lyrae variables 
B) T Tauri variables 
C) Cepheids 
D) cataclysmic variables 
E) planetary nebulae

Question 16

In the Galactic halo, we do NOT find:

Accepted Answer

A) tidal streams. 
B) globular clusters. 
C) small satellite galaxies. 
D) spiral arms. 
E) old white dwarfs. 
A) tidal streams. 
B) globular clusters. 
C) small satellite galaxies. 
D) spiral arms. 
E) old white dwarfs.

Question 17

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 18

Based on star counts, 100 years ago most astronomers thought:

Accepted Answer

A) we lay about 30,000 ly out from the center of the Galaxy. 
B) we lay near the center of a disk about 10 kpc wide and 2 kpc thick. 
C) we lay in a spiral arm of the largest galaxy in the universe. 
D) we lay near the edge of the only galaxy in the universe. 
E) we were not a part of any structure larger than the known solar system. 
A) we lay about 30,000 ly out from the center of the Galaxy. 
B) we lay near the center of a disk about 10 kpc wide and 2 kpc thick. 
C) we lay in a spiral arm of the largest galaxy in the universe. 
D) we lay near the edge of the only galaxy in the universe. 
E) we were not a part of any structure larger than the known solar system.

Question 19

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 20

How are Cepheids and RR Lyrae stars different?

Accepted Answer

Cepheids are large mass variable stars w

Exam 23: The Milky Way Galaxy: a Spiral in Space

The first attempt to map the Galaxy via star counts was done by:

Shapley correctly argued that the rotation of the spiral nebulae proved they could not be verydistant.

In age, Population I stars are typically much ________ than those of Population II.

Spiral arms are regions of star formation, which accounts for their blue color.

What use are 21 cm radio waves to galactic astronomers?

Density waves may explain:

These objects are no longer considered a good explanation for the dark matter in the Galactichalo.

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

The region on the H-R diagram where pulsating variables occur is called the:

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

Of what is the Galactic halo presumed to be composed? What evidence supports thisconclusion?

The majority of the mass of the Milky Way lies farther out than the Sun's orbit.

The interstellar ________ absorbs light from stars and makes them appear fainter and redderthan they otherwise would appear.

From Earth, the view of the Milky Way is a thin band of stars across the night sky. The partof the Milky Way Galaxy that is described here is the:

For what type of object is the period-luminosity relation used for determining distances?

In the Galactic halo, we do NOT find:

The period-luminosity relation is critical in finding distances with:

Based on star counts, 100 years ago most astronomers thought:

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

How are Cepheids and RR Lyrae stars different?

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information From the Cosmos

Spectroscopy: the Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earths Sister Planet

Mars: a Near Miss for Life

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants, Dwarfs, and the Main Sequence

The Interstellar Medium: Gas and Dust Among the Stars

Star Formation: a Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae, Supernovae, and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

Life in the Universe: Are We Alone

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