Question 1

Could the gold in the jewelry you are wearing have any connection with neutron stars?

Accepted Answer

A)  No. We do not expect neutron stars to eject any significant amount of material into the Galaxy. 
B)  Yes. Some of the gold may have been created in collisions between neutron stars in binary systems. 
C)  No. Some of the hydrogen in Earth's water may have been ejected from neutron stars as high-energy protons, but all heavy elements come from supernova explosions of normal stars. 
D)  Yes. The neutrons in the gold nuclei were very likely ejected from individual neutron stars. 
A)  No. We do not expect neutron stars to eject any significant amount of material into the Galaxy. 
B)  Yes. Some of the gold may have been created in collisions between neutron stars in binary systems. 
C)  No. Some of the hydrogen in Earth's water may have been ejected from neutron stars as high-energy protons, but all heavy elements come from supernova explosions of normal stars. 
D)  Yes. The neutrons in the gold nuclei were very likely ejected from individual neutron stars.

Question 2

What method is used by astronomers to infer the existence in space of a dark object of about 5 solar masses,such as a black hole?

Accepted Answer

A)  infrared imaging of a region whose effective temperature is lower than the cosmic microwave background, rendering it dark 
B)  measurement of the gravitational redshift of spectral lines in the spectrum of the object 
C)  measurement of the effect of its gravitational force on a companion object in a binary system 
D)  estimation of the luminosity of the object and the application of the mass-luminosity relationship 
A)  infrared imaging of a region whose effective temperature is lower than the cosmic microwave background, rendering it dark 
B)  measurement of the gravitational redshift of spectral lines in the spectrum of the object 
C)  measurement of the effect of its gravitational force on a companion object in a binary system 
D)  estimation of the luminosity of the object and the application of the mass-luminosity relationship

Question 3

Observing neutrinos from SN 1987A was a substantial part of the study of the supernova.Each statement about these neutrinos is true EXCEPT ONE.Which is the exception?

Accepted Answer

A)  The neutrinos arrived at Earth before the visible light. 
B)  Neutrino detectors using Cerenkov radiation need not be pointed at their targets, so the neutrinos could be detected, even though we were not excepting them. 
C)  Only neutrino detectors in the southern hemisphere were able to record the event since the Large Magellanic Cloud is only visible. 
D)  The discovery of neutrinos from SN 1987A provided strong support for the theory that supernovae are caused by the collapse of a star's core. 
A)  The neutrinos arrived at Earth before the visible light. 
B)  Neutrino detectors using Cerenkov radiation need not be pointed at their targets, so the neutrinos could be detected, even though we were not excepting them. 
C)  Only neutrino detectors in the southern hemisphere were able to record the event since the Large Magellanic Cloud is only visible. 
D)  The discovery of neutrinos from SN 1987A provided strong support for the theory that supernovae are caused by the collapse of a star's core.

Question 4

One day,while straying dangerously close to a black hole,you notice that no matter how hard you try to remain at rest,you are inevitably drawn into the black hole unless you keep moving.What does this experience tell you about the black hole (other than that you should not be near it!)?

Accepted Answer

A)  The black hole is evaporating. 
B)  The black hole is supermassive. 
C)  The black hole is electrically charged. 
D)  The black hole is rotating. 
A)  The black hole is evaporating. 
B)  The black hole is supermassive. 
C)  The black hole is electrically charged. 
D)  The black hole is rotating.

Question 5

If you stay on Earth while a friend races off in a rocket at close to the speed of light,then,according to special relativity,you will see a clock on the rocket appear to tick more slowly than the one on your wall.If your friend looks back at your clock,then,according to the same theory,the friend will see your clock appear to tick:

Accepted Answer

A)  at the same speed as the clock on the rocket. 
B)  faster than the clock on the rocket. 
C)  faster or slower than the clock on the rocket, depending on the direction of travel of the rocket compared with Earth. 
D)  slower than the clock on the rocket. 
A)  at the same speed as the clock on the rocket. 
B)  faster than the clock on the rocket. 
C)  faster or slower than the clock on the rocket, depending on the direction of travel of the rocket compared with Earth. 
D)  slower than the clock on the rocket.

Question 6

A nova is an explosion involving a white dwarf.Can a white dwarf become a nova more than once? Why or why not?

Accepted Answer

A)  No. The white dwarf's magnetic field is eliminated in the explosion. 
B)  Yes. A white dwarf can become a nova more than once if its temperature is high enough for recurrent helium flashes in the core. 
C)  Yes, A white dwarf can become a nova more than once if it continues to receive matter from a companion star. 
D)  No. The white dwarf is destroyed in the explosion. 
A)  No. The white dwarf's magnetic field is eliminated in the explosion. 
B)  Yes. A white dwarf can become a nova more than once if its temperature is high enough for recurrent helium flashes in the core. 
C)  Yes, A white dwarf can become a nova more than once if it continues to receive matter from a companion star. 
D)  No. The white dwarf is destroyed in the explosion.

Question 7

A white dwarf is supported from collapse under gravity by:

Accepted Answer

A)  pressure of the gas heated by nuclear fusion reactions in its core. 
B)  centrifugal force due to rapid rotation. 
C)  degenerate-electron pressure in the compact interior. 
D)  pressure of the gas heated by nuclear fusion reactions in a shell around its core. 
A)  pressure of the gas heated by nuclear fusion reactions in its core. 
B)  centrifugal force due to rapid rotation. 
C)  degenerate-electron pressure in the compact interior. 
D)  pressure of the gas heated by nuclear fusion reactions in a shell around its core.

Question 8

Visible pulses are seen to accompany radio pulses from a neutron star only:

Accepted Answer

A)  from neutron stars that are high above the galactic plane, where visible light is not obscured by dust and gas. 
B)  if the neutron star is relatively young. 
C)  if the neutron star is part of a binary star system. 
D)  if the neutron star is relatively old since pulsars from recent supernova explosions produce only radio pulses. 
A)  from neutron stars that are high above the galactic plane, where visible light is not obscured by dust and gas. 
B)  if the neutron star is relatively young. 
C)  if the neutron star is part of a binary star system. 
D)  if the neutron star is relatively old since pulsars from recent supernova explosions produce only radio pulses.

Question 9

The periods of MOST pulsars _____ with time.

Accepted Answer

A)  increase 
B)  decrease 
C)  remain constant 
D)  alternately increase and decrease 
A)  increase 
B)  decrease 
C)  remain constant 
D)  alternately increase and decrease

Question 10

How must an object be moving for us to be able to use the theory of special relativity to describe the object?

Accepted Answer

A)  The object must be moving close to the speed of light; how speed and direction change is not important. 
B)  The object must be moving at a constant speed in a straight line; how fast it is moving is not important. 
C)  The object must be moving in a constant direction; how its speed changes is unimportant. 
D)  The object must be moving at a constant speed; whether the direction of motion changes is unimportant. 
A)  The object must be moving close to the speed of light; how speed and direction change is not important. 
B)  The object must be moving at a constant speed in a straight line; how fast it is moving is not important. 
C)  The object must be moving in a constant direction; how its speed changes is unimportant. 
D)  The object must be moving at a constant speed; whether the direction of motion changes is unimportant.

Question 11

What result might you expect in a binary system containing a white dwarf with a mass considerably below 1.4 M?

Accepted Answer

A)  a nova 
B)  a Type Ia supernova 
C)  a Type II supernova 
D)  a supernova remnant 
A)  a nova 
B)  a Type Ia supernova 
C)  a Type II supernova 
D)  a supernova remnant

Question 12

The nuclear process in which helium fusion occurs in the deep interiors of red giant stars produces:

Accepted Answer

A)  iron nuclei. 
B)  carbon and oxygen nuclei. 
C)  hydrogen nuclei by the splitting of helium nuclei. 
D)  pure energy from the nuclear mass. 
A)  iron nuclei. 
B)  carbon and oxygen nuclei. 
C)  hydrogen nuclei by the splitting of helium nuclei. 
D)  pure energy from the nuclear mass.

Question 13

The escape velocity of matter from the center of a black hole greater than 3 solar masses is:

Accepted Answer

A)  always exactly equal to the speed of light. 
B)  quite small. 
C)  greater than the speed of light. 
D)  about half the speed of light. 
A)  always exactly equal to the speed of light. 
B)  quite small. 
C)  greater than the speed of light. 
D)  about half the speed of light.

Question 14

A low-mass giant on the horizontal branch fuses hydrogen into helium in its core.The core temperature is insufficient to fuse helium into carbon.So what nuclear reaction does happen next?

Accepted Answer

A)  shell helium fusion 
B)  core oxygen fusion 
C)  shell beryllium fusion 
D)  core beryllium fusion 
A)  shell helium fusion 
B)  core oxygen fusion 
C)  shell beryllium fusion 
D)  core beryllium fusion

Question 15

A white dwarf is a(n):

Accepted Answer

A)  object like Jupiter that was not quite massive enough to become a star. 
B)  small, very hot, low-mass star. 
C)  type of small protostar. 
D)  hot, main-sequence star. 
A)  object like Jupiter that was not quite massive enough to become a star. 
B)  small, very hot, low-mass star. 
C)  type of small protostar. 
D)  hot, main-sequence star.

Question 16

A child on a playground swing is swinging back and forth (one complete oscillation)once every 4 seconds,as seen by her father standing next to the swing.At the same time,a spaceship is hurtling by at a speed close to the speed of light.According to special relativity (and ignoring the Doppler effect for this question),her mother on the spaceship finds that the time for one full swing is:

Accepted Answer

A)  less than 4 seconds when the spaceship is approaching the swing and more than 4 seconds when it is moving away. 
B)  less than 4 seconds. 
C)  equal to 4 seconds. 
D)  more than 4 seconds. 
A)  less than 4 seconds when the spaceship is approaching the swing and more than 4 seconds when it is moving away. 
B)  less than 4 seconds. 
C)  equal to 4 seconds. 
D)  more than 4 seconds.

Question 17

It was recently discovered that the Scorpius-Centaurus OB association passed within 150 light-years of the solar system perhaps 2 million years ago.What is the significance?

Accepted Answer

A)  A supernova eruption in the association at that time may have sent shock waves that led to the collapse of a dark dust cloud to form the solar nebular disk. 
B)  A supernova eruption in the association at that time may have sent large amounts of radiation that overwhelmed the Earth's protective ozone layer and caused widespread biological extinctions. 
C)  The gravitational influence of the association probably caused the migration of the giant planets in our solar system to their present locations. 
D)  A supernova eruption in the association at that time may have been the source of the radioactive aluminum isotope that was once part of some meteorites, like the Allende meteorite. 
A)  A supernova eruption in the association at that time may have sent shock waves that led to the collapse of a dark dust cloud to form the solar nebular disk. 
B)  A supernova eruption in the association at that time may have sent large amounts of radiation that overwhelmed the Earth's protective ozone layer and caused widespread biological extinctions. 
C)  The gravitational influence of the association probably caused the migration of the giant planets in our solar system to their present locations. 
D)  A supernova eruption in the association at that time may have been the source of the radioactive aluminum isotope that was once part of some meteorites, like the Allende meteorite.

Question 18

The main source of cosmic rays,the high-energy atomic nuclei that strike Earth's atmosphere from interstellar space,is believed to be:

Accepted Answer

A)  rotating, magnetized neutron stars. 
B)  matter from accretion disks surrounding neutron stars and black holes. 
C)  acceleration of nuclei by neutrinos during supernova explosions. 
D)  supernova debris colliding with interstellar material. 
A)  rotating, magnetized neutron stars. 
B)  matter from accretion disks surrounding neutron stars and black holes. 
C)  acceleration of nuclei by neutrinos during supernova explosions. 
D)  supernova debris colliding with interstellar material.

Question 19

The core collapse phase at the end of the life of a massive star is triggered when:

Accepted Answer

A)  the helium flash and thermal pulses have expelled the star's envelope. 
B)  the density reaches the threshold for electron degeneracy pressure to become important. 
C)  nuclear fusion has produced a significant amount of iron in its core. 
D)  the core becomes as dense as an atomic nucleus. 
A)  the helium flash and thermal pulses have expelled the star's envelope. 
B)  the density reaches the threshold for electron degeneracy pressure to become important. 
C)  nuclear fusion has produced a significant amount of iron in its core. 
D)  the core becomes as dense as an atomic nucleus.

Question 20

What is the observed distribution of the longer-living gamma-ray bursters in the sky?

Accepted Answer

A)  They are concentrated primarily along the plane of the Milky Way, indicating an origin in the Galaxy. 
B)  They are uniform over the entire sky, indicating an origin at "cosmological" distances. 
C)  They are clumpy but not coinciding with any known galaxy clusters, indicating an origin in a new kind of astronomical object. 
D)  They are clumpy, approximately coinciding with large clusters of galaxies such as the Coma cluster. 
A)  They are concentrated primarily along the plane of the Milky Way, indicating an origin in the Galaxy. 
B)  They are uniform over the entire sky, indicating an origin at "cosmological" distances. 
C)  They are clumpy but not coinciding with any known galaxy clusters, indicating an origin in a new kind of astronomical object. 
D)  They are clumpy, approximately coinciding with large clusters of galaxies such as the Coma cluster.

Could the gold in the jewelry you are wearing have any connection with neutron stars?

What method is used by astronomers to infer the existence in space of a dark object of about 5 solar masses,such as a black hole?

Observing neutrinos from SN 1987A was a substantial part of the study of the supernova.Each statement about these neutrinos is true EXCEPT ONE.Which is the exception?

One day,while straying dangerously close to a black hole,you notice that no matter how hard you try to remain at rest,you are inevitably drawn into the black hole unless you keep moving.What does this experience tell you about the black hole (other than that you should not be near it!)?

A nova is an explosion involving a white dwarf.Can a white dwarf become a nova more than once? Why or why not?

A white dwarf is supported from collapse under gravity by:

Visible pulses are seen to accompany radio pulses from a neutron star only:

The periods of MOST pulsars _____ with time.

How must an object be moving for us to be able to use the theory of special relativity to describe the object?

What result might you expect in a binary system containing a white dwarf with a mass considerably below 1.4 M?

The nuclear process in which helium fusion occurs in the deep interiors of red giant stars produces:

The escape velocity of matter from the center of a black hole greater than 3 solar masses is:

A low-mass giant on the horizontal branch fuses hydrogen into helium in its core.The core temperature is insufficient to fuse helium into carbon.So what nuclear reaction does happen next?

A white dwarf is a(n):

It was recently discovered that the Scorpius-Centaurus OB association passed within 150 light-years of the solar system perhaps 2 million years ago.What is the significance?

The main source of cosmic rays,the high-energy atomic nuclei that strike Earth's atmosphere from interstellar space,is believed to be:

The core collapse phase at the end of the life of a massive star is triggered when:

What is the observed distribution of the longer-living gamma-ray bursters in the sky?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Galaxies

Cosmology

Astrobiology

Filters

Exam 12: The Deaths and Remnants of Stars

Could the gold in the jewelry you are wearing have any connection with neutron stars?

What method is used by astronomers to infer the existence in space of a dark object of about 5 solar masses,such as a black hole?

Observing neutrinos from SN 1987A was a substantial part of the study of the supernova.Each statement about these neutrinos is true EXCEPT ONE.Which is the exception?

One day,while straying dangerously close to a black hole,you notice that no matter how hard you try to remain at rest,you are inevitably drawn into the black hole unless you keep moving.What does this experience tell you about the black hole (other than that you should not be near it!)?

A nova is an explosion involving a white dwarf.Can a white dwarf become a nova more than once? Why or why not?

A white dwarf is supported from collapse under gravity by:

Visible pulses are seen to accompany radio pulses from a neutron star only:

The periods of MOST pulsars _____ with time.

How must an object be moving for us to be able to use the theory of special relativity to describe the object?

What result might you expect in a binary system containing a white dwarf with a mass considerably below 1.4 M?

The nuclear process in which helium fusion occurs in the deep interiors of red giant stars produces:

The escape velocity of matter from the center of a black hole greater than 3 solar masses is:

A low-mass giant on the horizontal branch fuses hydrogen into helium in its core.The core temperature is insufficient to fuse helium into carbon.So what nuclear reaction does happen next?

A white dwarf is a(n):

It was recently discovered that the Scorpius-Centaurus OB association passed within 150 light-years of the solar system perhaps 2 million years ago.What is the significance?

The main source of cosmic rays,the high-energy atomic nuclei that strike Earth's atmosphere from interstellar space,is believed to be:

The core collapse phase at the end of the life of a massive star is triggered when:

What is the observed distribution of the longer-living gamma-ray bursters in the sky?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Galaxies

Cosmology

Astrobiology

Filters