Question 1

If you had something the size of a sugar cube that was made of neutron star matter, it would weigh .

Accepted Answer

A) about 50 pounds 
B) as much as the entire Earth 
C) about as much as a truck 
D) about as much as a large mountain 
A) about 50 pounds 
B) as much as the entire Earth 
C) about as much as a truck 
D) about as much as a large mountain

Question 2

Which of the following statements about gamma ray bursts is not true?

Accepted Answer

A) The events responsible for gamma ray bursts apparently produce only gamma rays, and no other light that we can hope to detect. 
B) Gamma ray bursts are among the most luminous events that ever occur in the universe. 
C) Based on their distribution in the sky, we can rule out a connection between gamma ray bursts and X- ray binaries in the Milky Way Galaxy. 
D) Gamma ray bursts were originally discovered by satellites designed to look for signs of nuclear bomb tests on Earth. 
A) The events responsible for gamma ray bursts apparently produce only gamma rays, and no other light that we can hope to detect. 
B) Gamma ray bursts are among the most luminous events that ever occur in the universe. 
C) Based on their distribution in the sky, we can rule out a connection between gamma ray bursts and X- ray binaries in the Milky Way Galaxy. 
D) Gamma ray bursts were originally discovered by satellites designed to look for signs of nuclear bomb tests on Earth.

Question 3

How does an accretion disk around a neutron star differ from an accretion disk around a white dwarf?

Accepted Answer

A) The accretion disk around a neutron star is made mostly of helium while the accretion disk around a white dwarf is made mostly of hydrogen. 
B) The accretion disk around a neutron star is more likely to give birth to planets. 
C) The accretion disk around a neutron star always contains much more mass. 
D) The accretion disk around a neutron star is much hotter and emits higher- energy radiation. 
A) The accretion disk around a neutron star is made mostly of helium while the accretion disk around a white dwarf is made mostly of hydrogen. 
B) The accretion disk around a neutron star is more likely to give birth to planets. 
C) The accretion disk around a neutron star always contains much more mass. 
D) The accretion disk around a neutron star is much hotter and emits higher- energy radiation.

Question 4

Why do white- dwarf supernovae all have the same maximum luminosity?

Accepted Answer

White- dwarf supernovae occur when the m

Question 5

Rank the following 4 items in order of increasing density (low to high).

Accepted Answer

A) main- sequence star, white dwarf, neutron star, black hole singularity 
B) main- sequence star, neutron star, white dwarf, black hole singularity 
C) main- sequence star, black hole singularity, neutron star, white dwarf 
D) black hole singularity, main- sequence star, white dwarf, neutron star 
A) main- sequence star, white dwarf, neutron star, black hole singularity 
B) main- sequence star, neutron star, white dwarf, black hole singularity 
C) main- sequence star, black hole singularity, neutron star, white dwarf 
D) black hole singularity, main- sequence star, white dwarf, neutron star

Question 6

You are studying a mystery companion to an evolved star, with mass transfer happening. Which of the following properties suggests that the companion is definitely a black hole?

Accepted Answer

A) The mystery companion has a mass of over 3 solar masses. 
B) The mystery companion gives off periodic X- ray bursts. 
C) The mystery companion has an X- ray emitting accretion disk. 
D) The mystery companion has a mass of over 1.4 solar masses. 
A) The mystery companion has a mass of over 3 solar masses. 
B) The mystery companion gives off periodic X- ray bursts. 
C) The mystery companion has an X- ray emitting accretion disk. 
D) The mystery companion has a mass of over 1.4 solar masses.

Question 7

What is an X- ray burster? What causes the X- ray bursts?

Accepted Answer

It is a neutron star in a close binary s

Question 8

Observationally, how can we tell the difference between a white- dwarf supernova and a massive- star supernova?

Accepted Answer

A) The spectrum of a massive- star supernova shows prominent hydrogen lines, while the spectrum of a white- dwarf supernova does not. 
B) A massive- star supernova happens only once, while a white- dwarf supernova can repeat periodically. 
C) A massive- star supernova is brighter than a white- dwarf supernova. 
D) The light of a white- dwarf supernova fades steadily, while the light of a massive- star supernova continues to brighten for many weeks. 
E) We cannot yet tell the difference between a massive- star supernova and a white- dwarf supernova. 
A) The spectrum of a massive- star supernova shows prominent hydrogen lines, while the spectrum of a white- dwarf supernova does not. 
B) A massive- star supernova happens only once, while a white- dwarf supernova can repeat periodically. 
C) A massive- star supernova is brighter than a white- dwarf supernova. 
D) The light of a white- dwarf supernova fades steadily, while the light of a massive- star supernova continues to brighten for many weeks. 
E) We cannot yet tell the difference between a massive- star supernova and a white- dwarf supernova.

Question 9

Which of the following correctly describes how light will be affected as it tries to escape from a massive object?

Accepted Answer

A) Light escaping from a compact massive object, such as a neutron star, will be redshifted. 
B) Visible light escaping from a compact massive object, such as a neutron star, will be redshifted, but higher frequencies, such as X- rays and gamma rays, will not be affected. 
C) Light escaping from a compact massive object, such as a neutron star, will be blueshifted. 
D) Less energetic light will not be able to escape from a compact massive object, such as a neutron star, but more energetic light will be able to. 
E) Light doesn't have mass; therefore, it is not affected by gravity. 
A) Light escaping from a compact massive object, such as a neutron star, will be redshifted. 
B) Visible light escaping from a compact massive object, such as a neutron star, will be redshifted, but higher frequencies, such as X- rays and gamma rays, will not be affected. 
C) Light escaping from a compact massive object, such as a neutron star, will be blueshifted. 
D) Less energetic light will not be able to escape from a compact massive object, such as a neutron star, but more energetic light will be able to. 
E) Light doesn't have mass; therefore, it is not affected by gravity.

Question 10

Will our Sun ever undergo a white dwarf supernova explosion? Why or why not?

Accepted Answer

A) No, because the Sun's core will never be hot enough to fuse carbon and other heavier elements into iron. 
B) Yes, right at the end of its double- shell burning stage of life. 
C) Yes, about a million years after it becomes a white dwarf. 
D) No, because it is not orbited by another star. 
A) No, because the Sun's core will never be hot enough to fuse carbon and other heavier elements into iron. 
B) Yes, right at the end of its double- shell burning stage of life. 
C) Yes, about a million years after it becomes a white dwarf. 
D) No, because it is not orbited by another star.

Question 11

A neutron star is .

Accepted Answer

A) an object that will ultimately become a black hole 
B) the remains of a star that died by expelling its outer layers in a planetary nebula 
C) a star made mostly of elements with high atomic mass numbers, so that they have lots of neutrons 
D) the remains of a star that died in a massive star supernova (if no black hole were created) 
A) an object that will ultimately become a black hole 
B) the remains of a star that died by expelling its outer layers in a planetary nebula 
C) a star made mostly of elements with high atomic mass numbers, so that they have lots of neutrons 
D) the remains of a star that died in a massive star supernova (if no black hole were created)

Question 12

Which of the following statements about degeneracy pressure is not true?

Accepted Answer

A) Degeneracy pressure can arise only from interactions among electrons. 
B) Degeneracy pressure arises from a quantum mechanical effect that we don't notice in our daily lives. 
C) Black holes form when gravity overcomes neutron degeneracy pressure. 
D) Degeneracy pressure can continue to support an object against gravitational collapse even if the object becomes extremely cold. 
A) Degeneracy pressure can arise only from interactions among electrons. 
B) Degeneracy pressure arises from a quantum mechanical effect that we don't notice in our daily lives. 
C) Black holes form when gravity overcomes neutron degeneracy pressure. 
D) Degeneracy pressure can continue to support an object against gravitational collapse even if the object becomes extremely cold.

Question 13

Based on current understanding, the minimum mass of a black hole that forms during a massive star supernova is roughly _ .

Accepted Answer

A) 10 solar masses 
B) 3 solar masses 
C) 1)4 solar masses 
D) 0)5 solar masses 
A) 10 solar masses 
B) 3 solar masses 
C) 1)4 solar masses 
D) 0)5 solar masses

Question 14

Which of the following best describes what would happen if a 1.5- solar- mass neutron star, with a diameter of a few kilometers, were suddenly (for unexplained reason)to appear in your home town?

Accepted Answer

A) It would crash into Earth, throwing vast amounts of dust into the atmosphere that, in turn, would cool the Earth; this is probably what caused the extinction of the dinosaurs. 
B) The combined mass of Earth and the neutron star would cause the neutron star to collapse into a black hole. 
C) The entire Earth would end up as a thin layer, about 1 cm thick, over the surface of the neutron star. 
D) It would rapidly sink to the center of Earth. 
A) It would crash into Earth, throwing vast amounts of dust into the atmosphere that, in turn, would cool the Earth; this is probably what caused the extinction of the dinosaurs. 
B) The combined mass of Earth and the neutron star would cause the neutron star to collapse into a black hole. 
C) The entire Earth would end up as a thin layer, about 1 cm thick, over the surface of the neutron star. 
D) It would rapidly sink to the center of Earth.

Question 15

Our Sun will likely undergo a nova event in about 5 billion years.

Accepted Answer

A) True 
 B)False

Question 16

The maximum mass of a white dwarf is .

Accepted Answer

A) limitless; there is no theoretical limit to the maximum mass of a white dwarf 
B) about the mass of our Sun 
C) about 1.4 times the mass of our Sun 
D) about 3 times the mass of our Sun 
A) limitless; there is no theoretical limit to the maximum mass of a white dwarf 
B) about the mass of our Sun 
C) about 1.4 times the mass of our Sun 
D) about 3 times the mass of our Sun

Question 17

Suppose you find an X- ray binary system that shows X- ray bursts. Is it possible that this system consists of a red giant and a black hole? Why or why not?

Accepted Answer

No. X- ray bursts occur when a

Question 18

Imagine an advanced civilization living on a planet orbiting at a distance of 10 AU (1.5 billion kilometers)from a close binary star system that consists of a 15 MSun red giant star and a 10 MSun black hole. The black hole is surrounded by an accretion disk. Sometime within the next million years or so, the civilization's planet is likely to be doomed because .

Accepted Answer

A) jets of material shot out of the accretion disk will shoot down their planet 
B) tidal forces from the black hole will rip the planet apart 
C) the red giant star, which provides most of energy the civilization needs to exist, will soon be destroyed in the accretion disk 
D) the planet's orbit gradually will decay, as it is sucked in by the black hole 
E) the red giant will probably supernova within the next million years 
A) jets of material shot out of the accretion disk will shoot down their planet 
B) tidal forces from the black hole will rip the planet apart 
C) the red giant star, which provides most of energy the civilization needs to exist, will soon be destroyed in the accretion disk 
D) the planet's orbit gradually will decay, as it is sucked in by the black hole 
E) the red giant will probably supernova within the next million years

Question 19

After a massive- star supernova, what is left behind?

Accepted Answer

A) always a black hole 
B) always a white dwarf 
C) always a neutron star 
D) either a white dwarf or a neutron star 
E) either a neutron star or a black hole 
A) always a black hole 
B) always a white dwarf 
C) always a neutron star 
D) either a white dwarf or a neutron star 
E) either a neutron star or a black hole

Question 20

Which of the following is closest in size (radius)to a white dwarf?

Accepted Answer

A) the Sun 
B) a small city 
C) a basketball 
D) the Earth 
E) a football stadium 
A) the Sun 
B) a small city 
C) a basketball 
D) the Earth 
E) a football stadium

If you had something the size of a sugar cube that was made of neutron star matter, it would weigh .

Which of the following statements about gamma ray bursts is not true?

How does an accretion disk around a neutron star differ from an accretion disk around a white dwarf?

Why do white- dwarf supernovae all have the same maximum luminosity?

Rank the following 4 items in order of increasing density (low to high).

You are studying a mystery companion to an evolved star, with mass transfer happening. Which of the following properties suggests that the companion is definitely a black hole?

What is an X- ray burster? What causes the X- ray bursts?

Observationally, how can we tell the difference between a white- dwarf supernova and a massive- star supernova?

Which of the following correctly describes how light will be affected as it tries to escape from a massive object?

Will our Sun ever undergo a white dwarf supernova explosion? Why or why not?

A neutron star is .

Which of the following statements about degeneracy pressure is not true?

Based on current understanding, the minimum mass of a black hole that forms during a massive star supernova is roughly _ .

Which of the following best describes what would happen if a 1.5- solar- mass neutron star, with a diameter of a few kilometers, were suddenly (for unexplained reason)to appear in your home town?

Our Sun will likely undergo a nova event in about 5 billion years.

The maximum mass of a white dwarf is .

Suppose you find an X- ray binary system that shows X- ray bursts. Is it possible that this system consists of a red giant and a black hole? Why or why not?

After a massive- star supernova, what is left behind?

Which of the following is closest in size (radius)to a white dwarf?

A Modern View of the Universe

Discovering the Universe for Yourself

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

Light: the Cosmic Messenger

Formation of the Solar System

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

Other Planetary Systems: the New Science of Distant Worlds

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Exam 14: The Bizarre Stellar Graveyard

If you had something the size of a sugar cube that was made of neutron star matter, it would weigh .

Which of the following statements about gamma ray bursts is not true?

How does an accretion disk around a neutron star differ from an accretion disk around a white dwarf?

Why do white- dwarf supernovae all have the same maximum luminosity?

Rank the following 4 items in order of increasing density (low to high).

You are studying a mystery companion to an evolved star, with mass transfer happening. Which of the following properties suggests that the companion is definitely a black hole?

What is an X- ray burster? What causes the X- ray bursts?

Observationally, how can we tell the difference between a white- dwarf supernova and a massive- star supernova?

Which of the following correctly describes how light will be affected as it tries to escape from a massive object?

Will our Sun ever undergo a white dwarf supernova explosion? Why or why not?

A neutron star is .

Which of the following statements about degeneracy pressure is not true?

Based on current understanding, the minimum mass of a black hole that forms during a massive star supernova is roughly _ .

Which of the following best describes what would happen if a 1.5- solar- mass neutron star, with a diameter of a few kilometers, were suddenly (for unexplained reason)to appear in your home town?

Our Sun will likely undergo a nova event in about 5 billion years.

The maximum mass of a white dwarf is .

Suppose you find an X- ray binary system that shows X- ray bursts. Is it possible that this system consists of a red giant and a black hole? Why or why not?

After a massive- star supernova, what is left behind?

Which of the following is closest in size (radius)to a white dwarf?

A Modern View of 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 the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

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

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

Star Stuff

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

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

Life in the Universe

Filters