Question 1

Galactic disks appear blue because:

Accepted Answer

A)  they contain no G, K, or M dwarfs. 
B)  they contain only blue reflection nebulae. 
C)  dust obscures the longer, red, wavelengths. 
D)  O and B blue giants are much brighter than G, K, or M dwarfs. 
E)  dark matter gravitationally shifts all wavelengths towards the blue. 
A)  they contain no G, K, or M dwarfs. 
B)  they contain only blue reflection nebulae. 
C)  dust obscures the longer, red, wavelengths. 
D)  O and B blue giants are much brighter than G, K, or M dwarfs. 
E)  dark matter gravitationally shifts all wavelengths towards the blue.

Question 2

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 3

From the Sun,the distance to the Galactic Center is about:

Accepted Answer

A)  8 pc. 
B)  8,000 pc. 
C)  100,000 pc. 
D)  225 million pc. 
E)  100 billion pc. 
A)  8 pc. 
B)  8,000 pc. 
C)  100,000 pc. 
D)  225 million pc. 
E)  100 billion pc.

Question 4

The Milky Way is simply our edge-on view of our home Galaxy.

Accepted Answer

A) True 
 B)False

Question 5

Spiral arms are thought to be sites of ________,based on the observations of red HII regions and blue-white OB associations in and around these features.

Accepted Answer

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

Question 6

What is one of the differences between Cepheids and RR Lyrae variables?

Accepted Answer

A)  Cepheids are giants, but RR Lyrae stars are still on the main sequence. 
B)  All Cepheids have the same brightness, but RR Lyrae stars vary greatly in luminosity. 
C)  The period-luminosity relation holds only for RR Lyrae stars. 
D)  The pulsations of RR Lyrae stars are much less regular than those of Cepheids. 
E)  The RR Lyrae stars have much shorter periods than Cepheids. 
A)  Cepheids are giants, but RR Lyrae stars are still on the main sequence. 
B)  All Cepheids have the same brightness, but RR Lyrae stars vary greatly in luminosity. 
C)  The period-luminosity relation holds only for RR Lyrae stars. 
D)  The pulsations of RR Lyrae stars are much less regular than those of Cepheids. 
E)  The RR Lyrae stars have much shorter periods than Cepheids.

Question 7

Which is the correct description for the Sun's location in the Galaxy?

Accepted Answer

A)  at the outer edge of the bulge, but along the galactic equator 
B)  about 30,000 ly out in the halo 
C)  at the very outer edge of the disk, but in the galactic plane 
D)  in the disk in the inner region of the Sagittarius Arm 
E)  in the disk, and about halfway out from the center 
A)  at the outer edge of the bulge, but along the galactic equator 
B)  about 30,000 ly out in the halo 
C)  at the very outer edge of the disk, but in the galactic plane 
D)  in the disk in the inner region of the Sagittarius Arm 
E)  in the disk, and about halfway out from the center

Question 8

What perception of the Milky Way Galaxy did astronomers have in 1900?

Accepted Answer

A)  They believed that the Earth rested inside concentric spheres, with the Milky Way stars fixed to the outermost sphere. 
B)  They believed that the Milky Way was one of billions of galaxies in the universe. 
C)  They believed that the Milky Way was the entire universe. 
D)  They believed that, because the Sun was at the center of the Milky Way, it was impossible to see the rest of the universe. 
E)  They believed we were one of billions galaxies in an expanding universe. 
A)  They believed that the Earth rested inside concentric spheres, with the Milky Way stars fixed to the outermost sphere. 
B)  They believed that the Milky Way was one of billions of galaxies in the universe. 
C)  They believed that the Milky Way was the entire universe. 
D)  They believed that, because the Sun was at the center of the Milky Way, it was impossible to see the rest of the universe. 
E)  They believed we were one of billions galaxies in an expanding universe.

Question 9

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 10

It was the distribution of ________ that showed Harlow Shapley we were no where near the center of the Milky Way in the 1920s.

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 11

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.

Question 12

How does metal content vary between Population I and II? Why?

Accepted Answer

Older Population II stars are made of al

Question 13

Henrietta Leavitt's period-luminosity relation for ________ indicates that longer periods mean more luminosity.

Accepted Answer

The answer of Henrietta Leavitt's period-luminosity relation for ________ indicates...

Question 14

How does gravity lensing let us find massive dark objects?

Accepted Answer

When a black hole or brown dwarf passes

Question 15

Detailed study of stellar spectra in 1897,which enabled the development of the H-R diagram,was performed by:

Accepted Answer

A)  E.C. Pickering. 
B)  Harlow Shapley. 
C)  James Lick. 
D)  John Herschel. 
E)  Antonia Maury. 
A)  E.C. Pickering. 
B)  Harlow Shapley. 
C)  James Lick. 
D)  John Herschel. 
E)  Antonia Maury.

Question 16

How did Herschel try to map our Galaxy 200 years ago,and why did he fail?

Accepted Answer

His star counts revealed the g

Question 17

Although astronomers refer to the Galaxy's disk as rotating,the motion is really due to the ________ motion of each of the objects in the disk.

Accepted Answer

The answer of Although astronomers refer to the Galaxy's disk...

Question 18

The Harvard College Observatory Computers from c.1880 into the early 20th century were:

Accepted Answer

A)  the first digital computers. 
B)  not much different than cash registers. 
C)  functionally similar to the modern 4- function calculator. 
D)  a group of women who made important contributions to astronomy. 
E)  mechanically operated adding machines. 
A)  the first digital computers. 
B)  not much different than cash registers. 
C)  functionally similar to the modern 4- function calculator. 
D)  a group of women who made important contributions to astronomy. 
E)  mechanically operated adding machines.

Question 19

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 20

Who first attempted to find our position in the Galaxy,how did he do this,and why was his model flawed?

Accepted Answer

William Herschel relied on star counts,a

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

Galactic disks appear blue because:

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

From the Sun,the distance to the Galactic Center is about:

The Milky Way is simply our edge-on view of our home Galaxy.

Spiral arms are thought to be sites of ________,based on the observations of red HII regions and blue-white OB associations in and around these features.

What is one of the differences between Cepheids and RR Lyrae variables?

Which is the correct description for the Sun's location in the Galaxy?

What perception of the Milky Way Galaxy did astronomers have in 1900?

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

It was the distribution of ________ that showed Harlow Shapley we were no where near the center of the Milky Way in the 1920s.

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

How does metal content vary between Population I and II? Why?

Henrietta Leavitt's period-luminosity relation for ________ indicates that longer periods mean more luminosity.

How does gravity lensing let us find massive dark objects?

Detailed study of stellar spectra in 1897,which enabled the development of the H-R diagram,was performed by:

How did Herschel try to map our Galaxy 200 years ago,and why did he fail?

Although astronomers refer to the Galaxy's disk as rotating,the motion is really due to the ________ motion of each of the objects in the disk.

The Harvard College Observatory Computers from c.1880 into the early 20th century were:

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

Who first attempted to find our position in the Galaxy,how did he do this,and why was his model flawed?

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: Earth's 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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