Question 1

The mass of a supermassive black hole thought to power a typical bright active galactic nucleus is roughly ________.

Accepted Answer

A)  3 solar masses 
B)  10 solar masses 
C)  1 trillion solar masses 
D)  1 billion solar masses 
A)  3 solar masses 
B)  10 solar masses 
C)  1 trillion solar masses 
D)  1 billion solar masses

Question 2

A protogalactic cloud with very little angular momentum is more likely to form an elliptical galaxy than a spiral galaxy.

Accepted Answer

A) True 
 B)False

Question 3

The unusually bright centers found in some galaxies are called ________.

Accepted Answer

A)  active galactic nuclei 
B)  halos 
C)  supermassive black holes 
D)  starbursts 
A)  active galactic nuclei 
B)  halos 
C)  supermassive black holes 
D)  starbursts

Question 4

A standard candle is ________.

Accepted Answer

A)  a 7-cm-long wax candle 
B)  a light source of known luminosity 
C)  another name for a main-sequence star 
D)  another name for a barred-spiral galaxy 
A)  a 7-cm-long wax candle 
B)  a light source of known luminosity 
C)  another name for a main-sequence star 
D)  another name for a barred-spiral galaxy

Question 5

What is the most accurate way to determine the distance to a very distant galaxy?

Accepted Answer

A)  main-sequence fitting 
B)  Stellar parallax 
C)  Cepheid variables 
D)  white dwarf supernova 
E)  Hubble's law 
A)  main-sequence fitting 
B)  Stellar parallax 
C)  Cepheid variables 
D)  white dwarf supernova 
E)  Hubble's law

Question 6

What is a Cepheid variable?

Accepted Answer

A)  A type of very luminous star that makes an excellent standard candle 
B)  A bright source of variable X-ray emission, thought to harbor a supermassive black hole 
C)  A main-sequence star of spectral type B5 
D)  A type of galaxy that varies in its light output 
A)  A type of very luminous star that makes an excellent standard candle 
B)  A bright source of variable X-ray emission, thought to harbor a supermassive black hole 
C)  A main-sequence star of spectral type B5 
D)  A type of galaxy that varies in its light output

Question 7

Why are Cepheid variables important?

Accepted Answer

A)  Cepheid variables are stars that vary in brightness because they harbor a black hole. Therefore, they provide direct evidence for black holes. 
B)  Cepheids variables are pulsating stars whose pulsation periods are directly related to their true luminosities. Therefore they can be used as distance indicators. 
C)  Cepheids variables are a type of irregular galaxy, much more common in the early universe. Therefore they help to understand how galaxies formed. 
D)  Cepheids variables are supermassive stars that are on the verge of becoming supernovae. Therefore they allow us to choose candidates to watch if we hope to observe a supernova. 
A)  Cepheid variables are stars that vary in brightness because they harbor a black hole. Therefore, they provide direct evidence for black holes. 
B)  Cepheids variables are pulsating stars whose pulsation periods are directly related to their true luminosities. Therefore they can be used as distance indicators. 
C)  Cepheids variables are a type of irregular galaxy, much more common in the early universe. Therefore they help to understand how galaxies formed. 
D)  Cepheids variables are supermassive stars that are on the verge of becoming supernovae. Therefore they allow us to choose candidates to watch if we hope to observe a supernova.

Question 8

In 1924, Edwin Hubble proved that the Andromeda Galaxy lay far beyond the bounds of the Milky Way, thus putting to rest the idea that it might have been a cloud within our own galaxy. How was he able to prove this?

Accepted Answer

A)  By observing individual Cepheid variable stars in Andromeda and applying the period-luminosity relation 
B)  He was able to measure the parallax of the Andromeda Galaxy. 
C)  He found that the universe is expanding, and therefore concluded that Andromeda must lie outside our own galaxy. 
D)  He was the first person ever to look through a telescope at the object we now call the Andromeda Galaxy. 
A)  By observing individual Cepheid variable stars in Andromeda and applying the period-luminosity relation 
B)  He was able to measure the parallax of the Andromeda Galaxy. 
C)  He found that the universe is expanding, and therefore concluded that Andromeda must lie outside our own galaxy. 
D)  He was the first person ever to look through a telescope at the object we now call the Andromeda Galaxy.

Question 9

Compared to spiral galaxies, elliptical galaxies are

Accepted Answer

A)  redder and rounder. 
B)  redder and flattened. 
C)  bluer and rounder. 
D)  bluer and flattened. 
E)  always much smaller. 
A)  redder and rounder. 
B)  redder and flattened. 
C)  bluer and rounder. 
D)  bluer and flattened. 
E)  always much smaller.

Question 10

Ming measures a recession velocity of 2000 km/sec for a galaxy. About how far away is that galaxy if the Hubble constant is 20 km/sec/million light years? (Hint: be sure to check the units in your calculation.)

Accepted Answer

A)  100 light years 
B)  40 billion light years 
C)  100 million light years 
D)  40 thousand light years 
A)  100 light years 
B)  40 billion light years 
C)  100 million light years 
D)  40 thousand light years

Question 11

Which of the following phenomena is probably not related to the presence of a supermassive black hole?

Accepted Answer

A)  Quasars 
B)  The radio emission from radio galaxies 
C)  The huge jets seen emerging from the centers of some galaxies 
D)  The presence of globular clusters in the halos of galaxies 
A)  Quasars 
B)  The radio emission from radio galaxies 
C)  The huge jets seen emerging from the centers of some galaxies 
D)  The presence of globular clusters in the halos of galaxies

Question 12

What is main-sequence fitting?

Accepted Answer

A)  A method for determining the distance to a star cluster by assuming that its main sequence should line up with the main sequence on a standard H-R diagram 
B)  A method for determining the age of a star cluster 
C)  A way of forcing stars to fit into a standard main sequence, even when they have some unusual characteristics 
D)  The way we construct an H-R diagram by plotting the surface temperatures and luminosities of stars 
A)  A method for determining the distance to a star cluster by assuming that its main sequence should line up with the main sequence on a standard H-R diagram 
B)  A method for determining the age of a star cluster 
C)  A way of forcing stars to fit into a standard main sequence, even when they have some unusual characteristics 
D)  The way we construct an H-R diagram by plotting the surface temperatures and luminosities of stars

Question 13

Which of the following is a consequence of Hubble's Law?

Accepted Answer

A)  the Big Bang 
B)  all galaxies are moving away from us equally fast 
C)  the more distant a galaxy is from us, the faster it moves away from us 
D)  the closer a galaxy is to us, the faster it moves away from us 
E)  more distant galaxies appear younger 
A)  the Big Bang 
B)  all galaxies are moving away from us equally fast 
C)  the more distant a galaxy is from us, the faster it moves away from us 
D)  the closer a galaxy is to us, the faster it moves away from us 
E)  more distant galaxies appear younger

Question 14

Stars continue to form in the halo of our Galaxy today.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following is not a strong argument for the theory that some large elliptical galaxies formed as the result of galaxy collisions?

Accepted Answer

A)  Elliptical galaxies dominate the population in dense galaxy clusters. 
B)  Some ellipticals have stars and gas that rotate opposite to the rest of the galaxy. 
C)  Some elliptical galaxies are surrounded by shells of stars. 
D)  Computer simulations predict that the product of a galaxy collision is generally an elliptical galaxy. 
E)  Galaxy collisions are common and most galaxies in the universe are elliptical. 
A)  Elliptical galaxies dominate the population in dense galaxy clusters. 
B)  Some ellipticals have stars and gas that rotate opposite to the rest of the galaxy. 
C)  Some elliptical galaxies are surrounded by shells of stars. 
D)  Computer simulations predict that the product of a galaxy collision is generally an elliptical galaxy. 
E)  Galaxy collisions are common and most galaxies in the universe are elliptical.

Question 16

Why can't we see past the cosmological horizon?

Accepted Answer

A)  Beyond the cosmological horizon, we would be looking back to a time before the universe was born. 
B)  We do not have big enough telescopes. 
C)  The cosmological horizon is infinitely far away, and we can't see to infinity. 
D)  Every galaxy in the entire universe (not just the observable universe) exists within the cosmological horizon, so there's nothing to see beyond it. 
A)  Beyond the cosmological horizon, we would be looking back to a time before the universe was born. 
B)  We do not have big enough telescopes. 
C)  The cosmological horizon is infinitely far away, and we can't see to infinity. 
D)  Every galaxy in the entire universe (not just the observable universe) exists within the cosmological horizon, so there's nothing to see beyond it.

Question 17

Which types of galaxies have a clearly defined disk component?

Accepted Answer

A)  spirals only 
B)  ellipticals only 
C)  lenticulars only 
D)  irregulars only 
E)  spirals and lenticulars 
A)  spirals only 
B)  ellipticals only 
C)  lenticulars only 
D)  irregulars only 
E)  spirals and lenticulars

Question 18

Massive-star supernovae and white-dwarf supernovae work equally well as standard candles for measuring cosmic distances.

Accepted Answer

A) True 
 B)False

Question 19

There are more large spiral galaxies than there are large elliptical galaxies.

Accepted Answer

A) True 
 B)False

Question 20

Hubble's galaxy classification diagram (the "tuning fork") ________.

Accepted Answer

A)  shows how galaxies evolve from one form to another 
B)  explains active galactic nuclei 
C)  suggests the existence of black holes 
D)  relates galaxies according to their shapes, but not according to any evolutionary status 
A)  shows how galaxies evolve from one form to another 
B)  explains active galactic nuclei 
C)  suggests the existence of black holes 
D)  relates galaxies according to their shapes, but not according to any evolutionary status

The mass of a supermassive black hole thought to power a typical bright active galactic nucleus is roughly ________.

A protogalactic cloud with very little angular momentum is more likely to form an elliptical galaxy than a spiral galaxy.

The unusually bright centers found in some galaxies are called ________.

A standard candle is ________.

What is the most accurate way to determine the distance to a very distant galaxy?

What is a Cepheid variable?

Why are Cepheid variables important?

In 1924, Edwin Hubble proved that the Andromeda Galaxy lay far beyond the bounds of the Milky Way, thus putting to rest the idea that it might have been a cloud within our own galaxy. How was he able to prove this?

Compared to spiral galaxies, elliptical galaxies are

Ming measures a recession velocity of 2000 km/sec for a galaxy. About how far away is that galaxy if the Hubble constant is 20 km/sec/million light years? (Hint: be sure to check the units in your calculation.)

Which of the following phenomena is probably not related to the presence of a supermassive black hole?

What is main-sequence fitting?

Which of the following is a consequence of Hubble's Law?

Stars continue to form in the halo of our Galaxy today.

Which of the following is not a strong argument for the theory that some large elliptical galaxies formed as the result of galaxy collisions?

Why can't we see past the cosmological horizon?

Which types of galaxies have a clearly defined disk component?

Massive-star supernovae and white-dwarf supernovae work equally well as standard candles for measuring cosmic distances.

There are more large spiral galaxies than there are large elliptical galaxies.

Hubble's galaxy classification diagram (the "tuning fork") ________.

Our Place in the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

Star Stuff

Bizarre Stellar Graveyard

Our Galaxy

Dark Matter, Dark Energy, and the Fate of the Universe

The Beginning of Time

Life in the Universe

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Exam 15: Galaxies and the Foundation of Modern Cosmology

The mass of a supermassive black hole thought to power a typical bright active galactic nucleus is roughly ________.

A protogalactic cloud with very little angular momentum is more likely to form an elliptical galaxy than a spiral galaxy.

The unusually bright centers found in some galaxies are called ________.

A standard candle is ________.

What is the most accurate way to determine the distance to a very distant galaxy?

What is a Cepheid variable?

Why are Cepheid variables important?

In 1924, Edwin Hubble proved that the Andromeda Galaxy lay far beyond the bounds of the Milky Way, thus putting to rest the idea that it might have been a cloud within our own galaxy. How was he able to prove this?

Compared to spiral galaxies, elliptical galaxies are

Ming measures a recession velocity of 2000 km/sec for a galaxy. About how far away is that galaxy if the Hubble constant is 20 km/sec/million light years? (Hint: be sure to check the units in your calculation.)

Which of the following phenomena is probably not related to the presence of a supermassive black hole?

What is main-sequence fitting?

Which of the following is a consequence of Hubble's Law?

Stars continue to form in the halo of our Galaxy today.

Which of the following is not a strong argument for the theory that some large elliptical galaxies formed as the result of galaxy collisions?

Why can't we see past the cosmological horizon?

Which types of galaxies have a clearly defined disk component?

Massive-star supernovae and white-dwarf supernovae work equally well as standard candles for measuring cosmic distances.

There are more large spiral galaxies than there are large elliptical galaxies.

Hubble's galaxy classification diagram (the "tuning fork") ________.

Our Place in the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

Star Stuff

Bizarre Stellar Graveyard

Our Galaxy

Dark Matter, Dark Energy, and the Fate of the Universe

The Beginning of Time

Life in the Universe

Filters