Question 1

The center of the Milky Way lies in the direction of the constellation Cygnus.

Accepted Answer

A) True 
 B)False

Question 2

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 3

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 4

Of what is the galactic halo presumed to be composed? What evidence supports this conclusion?

Accepted Answer

The globular clusters are most obvious,b

Question 5

Between us and the Galactic Center,the Milky Way has a mass of:

Accepted Answer

A)  several hundred thousand suns. 
B)  one to two million suns. 
C)  250 million suns. 
D)  100 billion suns. 
E)  over a trillion suns. 
A)  several hundred thousand suns. 
B)  one to two million suns. 
C)  250 million suns. 
D)  100 billion suns. 
E)  over a trillion suns.

Question 6

The Galactic Year is the time for our solar system to orbit the Galaxy; it is about:

Accepted Answer

A)  15 million years. 
B)  225 million years. 
C)  4.5 billion years. 
D)  9.6 billion years. 
E)  13.5 billion years. 
A)  15 million years. 
B)  225 million years. 
C)  4.5 billion years. 
D)  9.6 billion years. 
E)  13.5 billion years.

Question 7

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 8

Which method relies on the mass of a dark object revealing its presence?

Accepted Answer

A)  asteroidal occultations 
B)  ring occultations 
C)  stellar eclipses 
D)  temporary brightening of a distant star by a gravity lens 
E)  pulsars slowing down irregularly 
A)  asteroidal occultations 
B)  ring occultations 
C)  stellar eclipses 
D)  temporary brightening of a distant star by a gravity lens 
E)  pulsars slowing down irregularly

Question 9

Early in the 20ᵗʰ century,our galaxy was estimated to be:

Accepted Answer

A)  about 100,000 ly in diameter. 
B)  about 35,000 ly (10 kpc) in diameter. 
C)  about 10 million ly in diameter. 
D)  not much larger than our solar system. 
E)  about 2.5 million ly in diameter. 
A)  about 100,000 ly in diameter. 
B)  about 35,000 ly (10 kpc) in diameter. 
C)  about 10 million ly in diameter. 
D)  not much larger than our solar system. 
E)  about 2.5 million ly in diameter.

Question 10

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.Th

Question 11

From the center of the Milky Way,10- kpc-long magnetized jets of high-energy particles are emitted.

Accepted Answer

A) True 
 B)False

Question 12

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

Accepted Answer

A) True 
 B)False

Question 13

Arcturus shows a large proper motion,almost perpendicular to the galactic plane.What Population does it belong to,and why?

Accepted Answer

Arcturus is the brightest Popu

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

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

Accepted Answer

The H-R diagrams of the globular cluster

Question 16

The leading explanation for the existence of spiral arms are:

Accepted Answer

A)  shock waves from cyclic supernovae explosions. 
B)  shock wave from the quasar-like eruption of the galactic core. 
C)  passages of spiral density waves through the interstellar medium. 
D)  passages of massive globular clusters through the galactic plane. 
E)  tidal streams of small galaxies being torn up by our monster Galaxy. 
A)  shock waves from cyclic supernovae explosions. 
B)  shock wave from the quasar-like eruption of the galactic core. 
C)  passages of spiral density waves through the interstellar medium. 
D)  passages of massive globular clusters through the galactic plane. 
E)  tidal streams of small galaxies being torn up by our monster Galaxy.

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

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

Question 19

In structure,our Milky Way is most similar to:

Accepted Answer

A)  the Large Magellanic Cloud. 
B)  an upscale version of a globular cluster. 
C)  M-31, the Andromeda Galaxy. 
D)  the Orion nebula. 
E)  None of these. 
A)  the Large Magellanic Cloud. 
B)  an upscale version of a globular cluster. 
C)  M-31, the Andromeda Galaxy. 
D)  the Orion nebula. 
E)  None of these.

Question 20

Harlow Shapley found the Milky Way was:

Accepted Answer

A)  centered on the Earth. 
B)  much smaller than previously thought. 
C)  rapidly expanding. 
D)  much larger than previously thought. 
E)  uniformly spherical in shape. 
A)  centered on the Earth. 
B)  much smaller than previously thought. 
C)  rapidly expanding. 
D)  much larger than previously thought. 
E)  uniformly spherical in shape.

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

The center of the Milky Way lies in the direction of the constellation Cygnus.

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

What use are 21 cm radio waves to galactic astronomers?

Of what is the galactic halo presumed to be composed? What evidence supports this conclusion?

Between us and the Galactic Center,the Milky Way has a mass of:

The Galactic Year is the time for our solar system to orbit the Galaxy; it is about:

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

Which method relies on the mass of a dark object revealing its presence?

Early in the 20ᵗʰ century,our galaxy was estimated to be:

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

From the center of the Milky Way,10- kpc-long magnetized jets of high-energy particles are emitted.

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

Arcturus shows a large proper motion,almost perpendicular to the galactic plane.What Population does it belong to,and why?

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

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

The leading explanation for the existence of spiral arms are:

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

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

In structure,our Milky Way is most similar to:

Harlow Shapley found the Milky Way was:

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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