Question 1

In 1785,William Herschel proposed that the solar system was at the center of the Milky Way Galaxy.How did he reach this conclusion?

Accepted Answer

A)  Like the ancient Greeks and many of their successors for over a thousand years,Herschel based his conclusion on the philosophical importance of Earth in the cosmos. 
B)  Herschel's observations suggested that the stars in the Milky Way Galaxy were distributed uniformly around Earth. 
C)  Herschel measured distances to globular clusters and determined that they were distributed uniformly around Earth. 
D)  Herschel determined that Cepheid variable stars in the Milky Way Galaxy were distributed uniformly around Earth. 
A)  Like the ancient Greeks and many of their successors for over a thousand years,Herschel based his conclusion on the philosophical importance of Earth in the cosmos. 
B)  Herschel's observations suggested that the stars in the Milky Way Galaxy were distributed uniformly around Earth. 
C)  Herschel measured distances to globular clusters and determined that they were distributed uniformly around Earth. 
D)  Herschel determined that Cepheid variable stars in the Milky Way Galaxy were distributed uniformly around Earth.

Question 2

When protons and electrons in neutral hydrogen spin,they act like tiny magnets.

Accepted Answer

A) True 
 B)False

Question 3

In the 1790s,Sir William Herschel tried to measure the Sun's position in our Galaxy by

Accepted Answer

A)  counting the density of stars in different directions along the Milky Way. 
B)  comparing our Galaxy with photographs of the Andromeda Galaxy. 
C)  measuring the locations of globular clusters around the Galaxy. 
D)  measuring distances to star clusters and H II regions in the disk of the Galaxy. 
A)  counting the density of stars in different directions along the Milky Way. 
B)  comparing our Galaxy with photographs of the Andromeda Galaxy. 
C)  measuring the locations of globular clusters around the Galaxy. 
D)  measuring distances to star clusters and H II regions in the disk of the Galaxy.

Question 4

What observations lead to the conclusion that the predominant constituent of our Galaxy is dark matter?

Accepted Answer

When the velocities determined by the Do

Question 5

If the Galaxy were spinning like a solid disk,stars closer to the center would

Accepted Answer

A)  orbit in much less time than stars farther out. 
B)  orbit in much greater time than stars farther out. 
C)  orbit in the same amount of time as stars farther out. 
D)  eventually fly apart from the immense speed. 
A)  orbit in much less time than stars farther out. 
B)  orbit in much greater time than stars farther out. 
C)  orbit in the same amount of time as stars farther out. 
D)  eventually fly apart from the immense speed.

Question 6

What are some speculations of what the mysterious dark matter is?

Accepted Answer

Dim objects with less than 1 solar mass

Question 7

Why are Cepheid variable stars so important to astronomers?

Accepted Answer

They are standard candles,meaning that w

Question 8

The one component of the material of the Milky Way Galaxy that prevents us from seeing and photographing the galactic center at optical wavelengths is

Accepted Answer

A)  very cold hydrogen gas. 
B)  the glare of light from nearby stars. 
C)  interstellar dust. 
D)  hot hydrogen gas. 
A)  very cold hydrogen gas. 
B)  the glare of light from nearby stars. 
C)  interstellar dust. 
D)  hot hydrogen gas.

Question 9

The 21-centimeter line is one of the most important wavelengths in radio astronomy.Its relatively long wavelength is important because long wavelengths

Accepted Answer

A)  are more likely to interact with clouds of gas and dust. 
B)  are more likely to pass through clouds of gas and dust. 
C)  carry more information than short wavelengths of the same energy. 
D)  can be detected with greater resolution than short wavelengths. 
A)  are more likely to interact with clouds of gas and dust. 
B)  are more likely to pass through clouds of gas and dust. 
C)  carry more information than short wavelengths of the same energy. 
D)  can be detected with greater resolution than short wavelengths.

Question 10

The Galaxy rotates like a solid disk,like a CD or DVD.

Accepted Answer

A) True 
 B)False

Question 11

In which spin configuration is the energy of the hydrogen atom GREATEST?

Accepted Answer

A)  When the proton spin and the electron spin are in the same direction 
B)  When the proton spin and the electron spin are perpendicular to each other 
C)  When the proton spin and the electron spin are in opposite directions 
D)  All of these spin configurations have the same energy;none is greatest. 
A)  When the proton spin and the electron spin are in the same direction 
B)  When the proton spin and the electron spin are perpendicular to each other 
C)  When the proton spin and the electron spin are in opposite directions 
D)  All of these spin configurations have the same energy;none is greatest.

Question 12

Which of the following is NOT useful for mapping the locations and shapes of the spiral arms of our Galaxy?

Accepted Answer

A)  The distribution of globular clusters 
B)  The distribution of O and B stars 
C)  The distribution of emission nebulae (H II regions) 
D)  The distribution of molecular clouds 
A)  The distribution of globular clusters 
B)  The distribution of O and B stars 
C)  The distribution of emission nebulae (H II regions) 
D)  The distribution of molecular clouds

Question 13

If there were no dark matter,how would the motion of stars around the core of a galaxy be changed?

Accepted Answer

The stars would not orbit as q

Question 14

Which kind of stars are the major source of energy for the heating of the dust clouds and the H II emission nebulae within the planes of the Milky Way and other galaxies?

Accepted Answer

A)  Hot,young O and B stars,via their UV radiation 
B)  The numerous old,red-giant K and M stars,via their IR heat radiation 
C)  Very hot white dwarf stars,the remnants of planetary nebulae in the gas clouds 
D)  The very many nova and supernova explosions of stars within the gas and dust clouds 
A)  Hot,young O and B stars,via their UV radiation 
B)  The numerous old,red-giant K and M stars,via their IR heat radiation 
C)  Very hot white dwarf stars,the remnants of planetary nebulae in the gas clouds 
D)  The very many nova and supernova explosions of stars within the gas and dust clouds

Question 15

What do we know about the geometry of the dark matter distribution in the vicinity of the Milky Way Galaxy?

Accepted Answer

A)  It appears to be a lens-shaped disk like the Galaxy's disk of visible stars,only larger. 
B)  It appears to be a spherical halo. 
C)  Dark matter,including that near the Milky Way Galaxy,appears to be part of a uniform density distribution,which fills all of space. 
D)  The geometry of the dark matter distribution,like its constituents,is totally unknown at the present time. 
A)  It appears to be a lens-shaped disk like the Galaxy's disk of visible stars,only larger. 
B)  It appears to be a spherical halo. 
C)  Dark matter,including that near the Milky Way Galaxy,appears to be part of a uniform density distribution,which fills all of space. 
D)  The geometry of the dark matter distribution,like its constituents,is totally unknown at the present time.

Question 16

X-ray flares around the core of the Galaxy flare dramatically in about 10 minutes;that shows that the flare's source can be no larger than

Accepted Answer

A)  10 light-minutes. 
B)  10 parsecs. 
C)  10 light-years. 
D)  10 AU. 
A)  10 light-minutes. 
B)  10 parsecs. 
C)  10 light-years. 
D)  10 AU.

Question 17

What is the significance of the object Sagittarius A* ("Sagittarius A-star")in our Galaxy?

Accepted Answer

A)  It appears to be a jet of material ejected from an accretion disk around a supermassive black hole in the galactic nucleus. 
B)  It is a globular cluster passing close to the galactic nucleus,and the RR Lyrae stars in it allow the distance to the galactic center to be calculated. 
C)  It is a bright,high-speed cloud of gas close to the galactic nucleus,which allows the mass of the nucleus to be calculated. 
D)  It appears to be the actual nucleus of the Galaxy. 
A)  It appears to be a jet of material ejected from an accretion disk around a supermassive black hole in the galactic nucleus. 
B)  It is a globular cluster passing close to the galactic nucleus,and the RR Lyrae stars in it allow the distance to the galactic center to be calculated. 
C)  It is a bright,high-speed cloud of gas close to the galactic nucleus,which allows the mass of the nucleus to be calculated. 
D)  It appears to be the actual nucleus of the Galaxy.

Question 18

X-ray flares coming from Sagittarius A* dramatically brighten in just 10 minutes,which shows that the source can be no larger than 10 light minutes across.

Accepted Answer

A) True 
 B)False

Question 19

A rotation curve is a graph of

Accepted Answer

A)  distance from the edge of a galaxy versus star luminosity. 
B)  speed of rotation versus distance from galactic center. 
C)  rotational speed versus star mass. 
D)  speed of rotation versus star temperature. 
A)  distance from the edge of a galaxy versus star luminosity. 
B)  speed of rotation versus distance from galactic center. 
C)  rotational speed versus star mass. 
D)  speed of rotation versus star temperature.

Question 20

What is the difference between RR Lyrae and Cepheid variables?

Accepted Answer

Both are variable stars,but RR

In 1785,William Herschel proposed that the solar system was at the center of the Milky Way Galaxy.How did he reach this conclusion?

When protons and electrons in neutral hydrogen spin,they act like tiny magnets.

In the 1790s,Sir William Herschel tried to measure the Sun's position in our Galaxy by

What observations lead to the conclusion that the predominant constituent of our Galaxy is dark matter?

If the Galaxy were spinning like a solid disk,stars closer to the center would

What are some speculations of what the mysterious dark matter is?

Why are Cepheid variable stars so important to astronomers?

The one component of the material of the Milky Way Galaxy that prevents us from seeing and photographing the galactic center at optical wavelengths is

The 21-centimeter line is one of the most important wavelengths in radio astronomy.Its relatively long wavelength is important because long wavelengths

The Galaxy rotates like a solid disk,like a CD or DVD.

In which spin configuration is the energy of the hydrogen atom GREATEST?

Which of the following is NOT useful for mapping the locations and shapes of the spiral arms of our Galaxy?

If there were no dark matter,how would the motion of stars around the core of a galaxy be changed?

Which kind of stars are the major source of energy for the heating of the dust clouds and the H II emission nebulae within the planes of the Milky Way and other galaxies?

What do we know about the geometry of the dark matter distribution in the vicinity of the Milky Way Galaxy?

X-ray flares around the core of the Galaxy flare dramatically in about 10 minutes;that shows that the flare's source can be no larger than

What is the significance of the object Sagittarius A* ("Sagittarius A-star")in our Galaxy?

X-ray flares coming from Sagittarius A* dramatically brighten in just 10 minutes,which shows that the source can be no larger than 10 light minutes across.

A rotation curve is a graph of

What is the difference between RR Lyrae and Cepheid variables?

Predicting the Motions of the Stars, Sun, and Moon

Decoding the Hidden Messages in Starlight

Analyzing Scales and Motions of the Universe

Exploring Our Evolving Solar System

Uncovering Earths Systems

Exploring Terrestrial Surface Processes and Atmospheres

Observing the Dynamic Giant Planets

Looking for Life Beyond Earth

Probing the Dynamic Sun

Observing Properties of Distant Stars

Inferring Patterns in Star Life Cycles

Predicting the Violent End of the Largest Stars

Investigating Other Galaxies

Observing the Evolution of the Universe

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Exam 13: Exploring Our Galaxy

In 1785,William Herschel proposed that the solar system was at the center of the Milky Way Galaxy.How did he reach this conclusion?

When protons and electrons in neutral hydrogen spin,they act like tiny magnets.

In the 1790s,Sir William Herschel tried to measure the Sun's position in our Galaxy by

What observations lead to the conclusion that the predominant constituent of our Galaxy is dark matter?

If the Galaxy were spinning like a solid disk,stars closer to the center would

What are some speculations of what the mysterious dark matter is?

Why are Cepheid variable stars so important to astronomers?

The one component of the material of the Milky Way Galaxy that prevents us from seeing and photographing the galactic center at optical wavelengths is

The 21-centimeter line is one of the most important wavelengths in radio astronomy.Its relatively long wavelength is important because long wavelengths

The Galaxy rotates like a solid disk,like a CD or DVD.

In which spin configuration is the energy of the hydrogen atom GREATEST?

Which of the following is NOT useful for mapping the locations and shapes of the spiral arms of our Galaxy?

If there were no dark matter,how would the motion of stars around the core of a galaxy be changed?

Which kind of stars are the major source of energy for the heating of the dust clouds and the H II emission nebulae within the planes of the Milky Way and other galaxies?

What do we know about the geometry of the dark matter distribution in the vicinity of the Milky Way Galaxy?

X-ray flares around the core of the Galaxy flare dramatically in about 10 minutes;that shows that the flare's source can be no larger than

What is the significance of the object Sagittarius A* ("Sagittarius A-star")in our Galaxy?

X-ray flares coming from Sagittarius A* dramatically brighten in just 10 minutes,which shows that the source can be no larger than 10 light minutes across.

A rotation curve is a graph of

What is the difference between RR Lyrae and Cepheid variables?

Predicting the Motions of the Stars, Sun, and Moon

Decoding the Hidden Messages in Starlight

Analyzing Scales and Motions of the Universe

Exploring Our Evolving Solar System

Uncovering Earths Systems

Exploring Terrestrial Surface Processes and Atmospheres

Observing the Dynamic Giant Planets

Looking for Life Beyond Earth

Probing the Dynamic Sun

Observing Properties of Distant Stars

Inferring Patterns in Star Life Cycles

Predicting the Violent End of the Largest Stars

Investigating Other Galaxies

Observing the Evolution of the Universe

Filters