Question 1

Fast radio bursts are thought to originate from outside the Milky Way. Why have astronomers reached this conclusion?

Accepted Answer

A)  No source in the Galaxy could produce such prodigious energy and be invisible at other wavelengths. 
B)  The bursts experience time dilation. 
C)  The bursts are observed at a wide range of declinations and right ascensions. 
D)  The bursts are exceptionally luminous. 
A)  No source in the Galaxy could produce such prodigious energy and be invisible at other wavelengths. 
B)  The bursts experience time dilation. 
C)  The bursts are observed at a wide range of declinations and right ascensions. 
D)  The bursts are exceptionally luminous.

Question 2

Could the gold on Earth have any connection with neutron stars?

Accepted Answer

A)  No. Neutron stars do not eject any significant amount of material into the Galaxy. 
B)  Yes. Some of the gold was 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. Neutron stars do not eject any significant amount of material into the Galaxy. 
B)  Yes. Some of the gold was 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 3

In 2004 astronomers made a significant discovery that enabled them to test some of the predictions of general relativity. What was this discovery?

Accepted Answer

A)  a neutron star with a mass more than 100 times the mass of the Sun 
B)  two neutron stars collided with each other 
C)  a pulsar that was not precessing and, in fact, that aimed its radiation beam directly at Earth 
D)  two pulsars in orbit around each other 
A)  a neutron star with a mass more than 100 times the mass of the Sun 
B)  two neutron stars collided with each other 
C)  a pulsar that was not precessing and, in fact, that aimed its radiation beam directly at Earth 
D)  two pulsars in orbit around each other

Question 4

The formation of an iron core is an important stage in the development of a supernova because

Accepted Answer

A)  iron nuclei cannot participate in nuclear reactions. 
B)  when iron nuclei undergo nuclear reactions, they always absorb energy. 
C)  when iron nuclei undergo nuclear reactions, they always give out energy. 
D)  iron nuclei make the core magnetic. 
A)  iron nuclei cannot participate in nuclear reactions. 
B)  when iron nuclei undergo nuclear reactions, they always absorb energy. 
C)  when iron nuclei undergo nuclear reactions, they always give out energy. 
D)  iron nuclei make the core magnetic.

Question 5

Which of these statements does NOT describe a consequence of core collapse at the end of the life of a massive star?

Accepted Answer

A)  The silicon core is converted to iron by fusion reactions. 
B)  Electrons combine with protons to form neutrons. 
C)  Great numbers of neutrinos are produced. 
D)  The core density approaches the density of an atomic nucleus. 
A)  The silicon core is converted to iron by fusion reactions. 
B)  Electrons combine with protons to form neutrons. 
C)  Great numbers of neutrinos are produced. 
D)  The core density approaches the density of an atomic nucleus.

Question 6

As a white dwarf evolves, the direction of its motion on the Hertzsprung-Russell diagram is from upper left to lower right, which means that

Accepted Answer

A)  it cools and becomes more luminous. 
B)  it cools and becomes less luminous. 
C)  it heats up and becomes more luminous. 
D)  it heats up and becomes less luminous. 
A)  it cools and becomes more luminous. 
B)  it cools and becomes less luminous. 
C)  it heats up and becomes more luminous. 
D)  it heats up and becomes less luminous.

Question 7

The nova phenomenon, an occasional and sometimes repeated intense brightening of a star by a factor of about 106, is caused by

Accepted Answer

A)  a beam of radiation from a nearby pulsar illuminating the surface of a red giant star and inducing rapid and intense heating. 
B)  the capture and rapid compression of matter by a black hole. 
C)  the explosion of a single massive star at the end of its thermonuclear fusion phases. 
D)  explosive hydrogen fusion on the surface of a white dwarf star after mass transfer from a companion star in a binary system. 
A)  a beam of radiation from a nearby pulsar illuminating the surface of a red giant star and inducing rapid and intense heating. 
B)  the capture and rapid compression of matter by a black hole. 
C)  the explosion of a single massive star at the end of its thermonuclear fusion phases. 
D)  explosive hydrogen fusion on the surface of a white dwarf star after mass transfer from a companion star in a binary system.

Question 8

When a typical nova explodes, it brightens in a few hours by a factor of

Accepted Answer

A)  108 to 1010. 
B)  2 to 5. 
C)  104 to 106. 
D)  10 to 100. 
A)  108 to 1010. 
B)  2 to 5. 
C)  104 to 106. 
D)  10 to 100.

Question 9

During the collision of two neutron stars, ejected neutrons form

Accepted Answer

A)  recurrent novae. 
B)  cosmic rays. 
C)  a neutron star ejected with a large velocity. 
D)  heavy elements. 
A)  recurrent novae. 
B)  cosmic rays. 
C)  a neutron star ejected with a large velocity. 
D)  heavy elements.

Question 10

Which of these is MOST likely to occur in a binary system containing a white dwarf with a mass of about 1.4 MSun?

Accepted Answer

A)  a nova 
B)  a Type Ia supernova 
C)  a Type II supernova 
D)  a planetary nebula 
A)  a nova 
B)  a Type Ia supernova 
C)  a Type II supernova 
D)  a planetary nebula

Question 11

Eta Carina is a massive binary star that experiences occasional outbursts or explosions as powerful as Type II supernovae. This is an example of a

Accepted Answer

A)  recurrent nova. 
B)  supernova impostor. 
C)  gamma-ray burst. 
D)  soft gamma-ray repeater. 
A)  recurrent nova. 
B)  supernova impostor. 
C)  gamma-ray burst. 
D)  soft gamma-ray repeater.

Question 12

The pulsed nature of the radiation at all wavelengths that is seen to come from a pulsar is produced by

Accepted Answer

A)  the rapid pulsation in size and brightness of a small white dwarf star. 
B)  the rapid rotation of a neutron star that is producing two oppositely directed beams of radiation. 
C)  the mutual eclipses of two very hot stars orbiting in a close binary system. 
D)  extremely hot matter that is rapidly orbiting a black hole just prior to descending into it. 
A)  the rapid pulsation in size and brightness of a small white dwarf star. 
B)  the rapid rotation of a neutron star that is producing two oppositely directed beams of radiation. 
C)  the mutual eclipses of two very hot stars orbiting in a close binary system. 
D)  extremely hot matter that is rapidly orbiting a black hole just prior to descending into it.

Question 13

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. How does the star produce energy?

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 14

What is the last nuclear fusion stage in the life of a low-mass star like the Sun?

Accepted Answer

A)  fusion of silicon nuclei to form iron 
B)  fusion of oxygen nuclei to form sulfur 
C)  fusion of helium nuclei to form carbon and oxygen 
D)  fusion of hydrogen nuclei to form helium 
A)  fusion of silicon nuclei to form iron 
B)  fusion of oxygen nuclei to form sulfur 
C)  fusion of helium nuclei to form carbon and oxygen 
D)  fusion of hydrogen nuclei to form helium

Question 15

Are crystalline stars or crystalline remnants of stars possible? Why or why not?

Accepted Answer

A)  No. Stars and stellar remnants are too hot to crystallize. 
B)  Yes. They are the likely outcome of the cooling of a white dwarf. 
C)  No. The forces needed to crystallize a star would actually cause the star to collapse gravitationally into a black hole. 
D)  Yes. They are the likely outcome of the creation of iron in the core of a massive star. 
A)  No. Stars and stellar remnants are too hot to crystallize. 
B)  Yes. They are the likely outcome of the cooling of a white dwarf. 
C)  No. The forces needed to crystallize a star would actually cause the star to collapse gravitationally into a black hole. 
D)  Yes. They are the likely outcome of the creation of iron in the core of a massive star.

Question 16

In 2017, astronomers observed the collision of two neutron stars

Accepted Answer

A)  through its gravitational wave signature. 
B)  through its neutrino production. 
C)  as a Type Ia supernova. 
D)  as a hypernova. 
A)  through its gravitational wave signature. 
B)  through its neutrino production. 
C)  as a Type Ia supernova. 
D)  as a hypernova.

Question 17

A nova is a sudden brightening of a star that occurs when

Accepted Answer

A)  material is transferred onto the surface of a white dwarf from a companion star in a binary system, then subsequently blasted into space by a runaway thermonuclear explosion (leaving the white dwarf intact to repeat the process). 
B)  material from a companion star is transferred onto the surface of a white dwarf star in a binary system, after which runaway carbon-fusion reactions cause the entire white dwarf to be destroyed in an explosion. 
C)  the electron degenerate iron core of a massive star collapses after its mass becomes greater than the Chandrasekhar mass limit. 
D)  material is transferred onto a neutron star from a companion star in a binary system, causing the neutron star to collapse into a black hole. 
A)  material is transferred onto the surface of a white dwarf from a companion star in a binary system, then subsequently blasted into space by a runaway thermonuclear explosion (leaving the white dwarf intact to repeat the process). 
B)  material from a companion star is transferred onto the surface of a white dwarf star in a binary system, after which runaway carbon-fusion reactions cause the entire white dwarf to be destroyed in an explosion. 
C)  the electron degenerate iron core of a massive star collapses after its mass becomes greater than the Chandrasekhar mass limit. 
D)  material is transferred onto a neutron star from a companion star in a binary system, causing the neutron star to collapse into a black hole.

Question 18

The last supernova in the Milky Way Galaxy that was visible to the naked eye was observed when?

Accepted Answer

A)  Astronomers have never seen a naked-eye supernova. 
B)  They are quite common, so one was observed within the last year. 
C)  There are reports of a supernova eruption in 1066. 
D)  Kepler observed one in 1604. 
A)  Astronomers have never seen a naked-eye supernova. 
B)  They are quite common, so one was observed within the last year. 
C)  There are reports of a supernova eruption in 1066. 
D)  Kepler observed one in 1604.

Question 19

The fraction of the mass of a low-mass star that is ejected in its evolutionary phases, up to and including the planetary nebula phase, is

Accepted Answer

A)  almost the entire star, more than 95%. 
B)  significant, up to 80%. 
C)  extremely small, less than 1 part in 104, since it is only the star's atmosphere that has been ejected. 
D)  very small, close to 10%. 
A)  almost the entire star, more than 95%. 
B)  significant, up to 80%. 
C)  extremely small, less than 1 part in 104, since it is only the star's atmosphere that has been ejected. 
D)  very small, close to 10%.

Question 20

"Starquakes" are the rearrangement of material in a neutron star, similar to an earthquake on Earth. Which one of these statements about starquakes is correct?

Accepted Answer

A)  Starquakes are triggered by instabilities in the neutron star's magnetic field. 
B)  Starquakes are caused by stresses in the crusts of neutron stars that form close binary systems and exert tremendous forces on each other. 
C)  Starquakes cause glitches in the pulsar period. 
D)  Starquakes cause rents in the crust of a neutron star and allow gamma rays and X-rays to escape from the interior, like the coronal holes in the Sun's atmosphere. 
A)  Starquakes are triggered by instabilities in the neutron star's magnetic field. 
B)  Starquakes are caused by stresses in the crusts of neutron stars that form close binary systems and exert tremendous forces on each other. 
C)  Starquakes cause glitches in the pulsar period. 
D)  Starquakes cause rents in the crust of a neutron star and allow gamma rays and X-rays to escape from the interior, like the coronal holes in the Sun's atmosphere.

Fast radio bursts are thought to originate from outside the Milky Way. Why have astronomers reached this conclusion?

Could the gold on Earth have any connection with neutron stars?

In 2004 astronomers made a significant discovery that enabled them to test some of the predictions of general relativity. What was this discovery?

The formation of an iron core is an important stage in the development of a supernova because

Which of these statements does NOT describe a consequence of core collapse at the end of the life of a massive star?

As a white dwarf evolves, the direction of its motion on the Hertzsprung-Russell diagram is from upper left to lower right, which means that

The nova phenomenon, an occasional and sometimes repeated intense brightening of a star by a factor of about 10⁶, is caused by

When a typical nova explodes, it brightens in a few hours by a factor of

During the collision of two neutron stars, ejected neutrons form

Which of these is MOST likely to occur in a binary system containing a white dwarf with a mass of about 1.4 M_Sun?

Eta Carina is a massive binary star that experiences occasional outbursts or explosions as powerful as Type II supernovae. This is an example of a

The pulsed nature of the radiation at all wavelengths that is seen to come from a pulsar is produced by

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. How does the star produce energy?

What is the last nuclear fusion stage in the life of a low-mass star like the Sun?

Are crystalline stars or crystalline remnants of stars possible? Why or why not?

In 2017, astronomers observed the collision of two neutron stars

A nova is a sudden brightening of a star that occurs when

The last supernova in the Milky Way Galaxy that was visible to the naked eye was observed when?

The fraction of the mass of a low-mass star that is ejected in its evolutionary phases, up to and including the planetary nebula phase, is

"Starquakes" are the rearrangement of material in a neutron star, similar to an earthquake on Earth. Which one of these statements about starquakes is correct?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 14: The Death of Stars

Fast radio bursts are thought to originate from outside the Milky Way. Why have astronomers reached this conclusion?

Could the gold on Earth have any connection with neutron stars?

In 2004 astronomers made a significant discovery that enabled them to test some of the predictions of general relativity. What was this discovery?

The formation of an iron core is an important stage in the development of a supernova because

Which of these statements does NOT describe a consequence of core collapse at the end of the life of a massive star?

As a white dwarf evolves, the direction of its motion on the Hertzsprung-Russell diagram is from upper left to lower right, which means that

The nova phenomenon, an occasional and sometimes repeated intense brightening of a star by a factor of about 106, is caused by

When a typical nova explodes, it brightens in a few hours by a factor of

During the collision of two neutron stars, ejected neutrons form

Which of these is MOST likely to occur in a binary system containing a white dwarf with a mass of about 1.4 MSun?

Eta Carina is a massive binary star that experiences occasional outbursts or explosions as powerful as Type II supernovae. This is an example of a

The pulsed nature of the radiation at all wavelengths that is seen to come from a pulsar is produced by

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. How does the star produce energy?

What is the last nuclear fusion stage in the life of a low-mass star like the Sun?

Are crystalline stars or crystalline remnants of stars possible? Why or why not?

In 2017, astronomers observed the collision of two neutron stars

A nova is a sudden brightening of a star that occurs when

The last supernova in the Milky Way Galaxy that was visible to the naked eye was observed when?

The fraction of the mass of a low-mass star that is ejected in its evolutionary phases, up to and including the planetary nebula phase, is

"Starquakes" are the rearrangement of material in a neutron star, similar to an earthquake on Earth. Which one of these statements about starquakes is correct?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

The nova phenomenon, an occasional and sometimes repeated intense brightening of a star by a factor of about 10⁶, is caused by

Which of these is MOST likely to occur in a binary system containing a white dwarf with a mass of about 1.4 M_Sun?