Question 1

The study of supernova 1987A and the study of the Sun have at least one aspect in common, namely

Accepted Answer

A)  each of these objects was not as bright as it was predicted to be theoretically. 
B)  magnetic effects provided much of the information. 
C)  the information provided by nonvisible radiation contradicted that from visible observations. 
D)  the most direct information about the core was carried by neutrinos. 
A)  each of these objects was not as bright as it was predicted to be theoretically. 
B)  magnetic effects provided much of the information. 
C)  the information provided by nonvisible radiation contradicted that from visible observations. 
D)  the most direct information about the core was carried by neutrinos.

Question 2

Which of these processes is NOT involved in the supernova explosion of a massive star?

Accepted Answer

A)  photodisintegration of nuclei by gamma rays 
B)  helium flash in the star's core 
C)  collapse of the star's core 
D)  passage of a shock wave through the star's envelope 
A)  photodisintegration of nuclei by gamma rays 
B)  helium flash in the star's core 
C)  collapse of the star's core 
D)  passage of a shock wave through the star's envelope

Question 3

The Sun will end its life by becoming a

Accepted Answer

A)  molecular cloud. 
B)  black hole. 
C)  white dwarf. 
D)  pulsar. 
A)  molecular cloud. 
B)  black hole. 
C)  white dwarf. 
D)  pulsar.

Question 4

The rings of material surrounding the SN 1987A remnant glow. In what region of the spectrum do they emit most of their radiation?

Accepted Answer

A)  The rings are mostly hydrogen shed from the star's envelope, so the H $\alpha$  line might be expected to be prominent in the resulting spectrum. 
B)  The rings glow because of natural radioactivity, which emits mostly gamma radiation. 
C)  The heavy elements created in the supernova have complex atomic structures that emit a continuous spectrum. 
D)  Only the longest radio waves can penetrate the dust clouds surrounding the supernova remnant. 
A)  The rings are mostly hydrogen shed from the star's envelope, so the H $\alpha$  line might be expected to be prominent in the resulting spectrum. 
B)  The rings glow because of natural radioactivity, which emits mostly gamma radiation. 
C)  The heavy elements created in the supernova have complex atomic structures that emit a continuous spectrum. 
D)  Only the longest radio waves can penetrate the dust clouds surrounding the supernova remnant.

Question 5

The main reason for the observed slowdown of many pulsars is

Accepted Answer

A)  friction between the stellar surface and the surrounding nebular material. 
B)  a slow buildup of the magnetic field; rotational energy is transferred to magnetic energy. 
C)  the loss of rotational energy to provide energy for the emission of radiation. 
D)  the slowing of rotation caused by slow expansion and redistribution of mass of the source, similar to the slowdown of a spinning skater. 
A)  friction between the stellar surface and the surrounding nebular material. 
B)  a slow buildup of the magnetic field; rotational energy is transferred to magnetic energy. 
C)  the loss of rotational energy to provide energy for the emission of radiation. 
D)  the slowing of rotation caused by slow expansion and redistribution of mass of the source, similar to the slowdown of a spinning skater.

Question 6

A Type Ia supernova is the

Accepted Answer

A)  collapse of a blue supergiant star to form a black hole. 
B)  explosion of a red giant star as a result of a helium flash in its core. 
C)  explosion of a white dwarf in a binary star system after mass has been transferred onto it from its companion. 
D)  explosion of a massive star after silicon fusion has produced a core of iron nuclei. 
A)  collapse of a blue supergiant star to form a black hole. 
B)  explosion of a red giant star as a result of a helium flash in its core. 
C)  explosion of a white dwarf in a binary star system after mass has been transferred onto it from its companion. 
D)  explosion of a massive star after silicon fusion has produced a core of iron nuclei.

Question 7

What is a hypernova?

Accepted Answer

A)  a recurrent nova on the surface of a white dwarf star 
B)  a runaway nuclear reaction on the surface of a neutron star 
C)  a stellar explosion that is 10 times brighter and lasts several times longer than "ordinary" supernovae 
D)  the collision of two neutron stars 
A)  a recurrent nova on the surface of a white dwarf star 
B)  a runaway nuclear reaction on the surface of a neutron star 
C)  a stellar explosion that is 10 times brighter and lasts several times longer than "ordinary" supernovae 
D)  the collision of two neutron stars

Question 8

When mass transfer in a binary system involves mass transferred to a white dwarf, the result is a nova. When the mass is transferred to a neutron star, the result is a(n)

Accepted Answer

A)  magnetar. 
B)  soft gamma-ray repeater. 
C)  black hole. 
D)  X-ray burster. 
A)  magnetar. 
B)  soft gamma-ray repeater. 
C)  black hole. 
D)  X-ray burster.

Question 9

After the material in the core of a massive star has been converted to iron by thermonuclear reactions, further energy can be released to heat the core only by

Accepted Answer

A)  gravitational contraction. 
B)  nuclear fission, or splitting of nuclei. 
C)  the absorption of neutrinos. 
D)  thermonuclear fusion of iron into heavier elements. 
A)  gravitational contraction. 
B)  nuclear fission, or splitting of nuclei. 
C)  the absorption of neutrinos. 
D)  thermonuclear fusion of iron into heavier elements.

Question 10

During its life, a massive star creates heavier and heavier elements in its core through thermonuclear fusion, leading up to silicon and iron. What is the fate of the iron that is created?

Accepted Answer

A)  The nuclei are split apart by neutron bombardment, creating lighter elements such as carbon, oxygen, and neon. 
B)  The iron is locked up inside the star forever. 
C)  The iron is destroyed by later thermonuclear fusion reactions in the core that create even heavier elements such as lead, gold, and uranium. 
D)  The iron is torn apart by high-energy photons at the end of the star's life. 
A)  The nuclei are split apart by neutron bombardment, creating lighter elements such as carbon, oxygen, and neon. 
B)  The iron is locked up inside the star forever. 
C)  The iron is destroyed by later thermonuclear fusion reactions in the core that create even heavier elements such as lead, gold, and uranium. 
D)  The iron is torn apart by high-energy photons at the end of the star's life.

Question 11

In the binary pulsar Hercules X-1 the periodic Doppler shift, once every 1.7 days, was discovered rather quickly. Even though the binary pulsar Centaurus X-3 was discovered earlier, its Doppler shift was discovered only much later. What might be a reason for this?

Accepted Answer

A)  The orbital plane of Centaurus X-3 is in the plane of the sky and therefore has no radial motion and no Doppler shift. 
B)  Centaurus X-3 is too far away to see the Doppler shift easily. 
C)  The orbital period of Centaurus X-3, 2087 days, suggests that it moves relatively slowly. 
D)  The binary companion of Centaurus X-3 is a black hole that distorts the pattern of its radiation output. 
A)  The orbital plane of Centaurus X-3 is in the plane of the sky and therefore has no radial motion and no Doppler shift. 
B)  Centaurus X-3 is too far away to see the Doppler shift easily. 
C)  The orbital period of Centaurus X-3, 2087 days, suggests that it moves relatively slowly. 
D)  The binary companion of Centaurus X-3 is a black hole that distorts the pattern of its radiation output.

Question 12

In the study of neutron stars, what is a "glitch"?

Accepted Answer

A)  sudden change in the rotation rate of the neutron star 
B)  change in the pulse period of a neutron star due to the gravitational effect of an orbiting planet 
C)  sudden pulse of light from the neutron star 
D)  collision between two neutron stars 
A)  sudden change in the rotation rate of the neutron star 
B)  change in the pulse period of a neutron star due to the gravitational effect of an orbiting planet 
C)  sudden pulse of light from the neutron star 
D)  collision between two neutron stars

Question 13

Measurements suggest that light first arrived at Earth from the Cassiopeia A supernova about 300 years ago and that this supernova is about 10,000 ly distant from Earth. When did the explosion actually occur?

Accepted Answer

A)  It is not possible to determine when the explosion occurred from the information given. 
B)  9700 years ago, or about 7700 B.C. 
C)  10,300 years ago, or about 8300 B.C. 
D)  300 years ago, or about A.D. 1700. 
A)  It is not possible to determine when the explosion occurred from the information given. 
B)  9700 years ago, or about 7700 B.C. 
C)  10,300 years ago, or about 8300 B.C. 
D)  300 years ago, or about A.D. 1700.

Question 14

A star at the tip of the asymptotic giant branch (AGB) is a

Accepted Answer

A)  cool main-sequence star. 
B)  blue supergiant. 
C)  star in its first red-giant phase. 
D)  red supergiant. 
A)  cool main-sequence star. 
B)  blue supergiant. 
C)  star in its first red-giant phase. 
D)  red supergiant.

Question 15

The event that follows the asymptotic giant branch (AGB) phase in the life of a low-mass star is

Accepted Answer

A)  the ejection of a planetary nebula. 
B)  core collapse and a supernova explosion. 
C)  helium flash and the start of helium fusion in the core. 
D)  the onset of hydrogen fusion in the core. 
A)  the ejection of a planetary nebula. 
B)  core collapse and a supernova explosion. 
C)  helium flash and the start of helium fusion in the core. 
D)  the onset of hydrogen fusion in the core.

Question 16

There is a mass limit for a star in the white-dwarf phase, the Chandrasekhar limit, beyond which the electron degeneracy pressure can no longer support the star against its own gravity. This limit is

Accepted Answer

A)  0.2 solar mass. 
B)  30 solar masses. 
C)  1.4 solar masses. 
D)  14 solar masses. 
A)  0.2 solar mass. 
B)  30 solar masses. 
C)  1.4 solar masses. 
D)  14 solar masses.

Question 17

Eta Carina is a

Accepted Answer

A)  supernova remnant. 
B)  active supermassive black hole. 
C)  star-forming region with many O and B stars. 
D)  binary star system that periodically undergoes powerful outbursts. 
A)  supernova remnant. 
B)  active supermassive black hole. 
C)  star-forming region with many O and B stars. 
D)  binary star system that periodically undergoes powerful outbursts.

Question 18

In terms of the evolutionary life of a star, at what stage is the Crab Nebula?

Accepted Answer

A)  middle-age: main-sequence star, relatively near the Sun 
B)  black hole: very late stage of evolution 
C)  beginning: nebula in which stars are forming 
D)  late: it is the remnant of a star explosion or supernova 
A)  middle-age: main-sequence star, relatively near the Sun 
B)  black hole: very late stage of evolution 
C)  beginning: nebula in which stars are forming 
D)  late: it is the remnant of a star explosion or supernova

Question 19

The source of the beams of electromagnetic radiation (including light in some cases) emitted by pulsars is

Accepted Answer

A)  charged particles traveling along the magnetic axes of rotating neutron stars; the particles emit light as they are accelerated. 
B)  electrons flowing out along the rotation axis of an accretion disk around a neutron star; the electrons are accelerated and hence emit light. 
C)  the surface of a normal star that has a white dwarf companion; the white dwarf creates a hot spot on the normal star that emits a beam of light as the stars rotate around each other. 
D)  jets of material flowing out along the rotation axis of the accretion disk around a black hole; collisions in the jets heat the material and produce light. 
A)  charged particles traveling along the magnetic axes of rotating neutron stars; the particles emit light as they are accelerated. 
B)  electrons flowing out along the rotation axis of an accretion disk around a neutron star; the electrons are accelerated and hence emit light. 
C)  the surface of a normal star that has a white dwarf companion; the white dwarf creates a hot spot on the normal star that emits a beam of light as the stars rotate around each other. 
D)  jets of material flowing out along the rotation axis of the accretion disk around a black hole; collisions in the jets heat the material and produce light.

Question 20

One distinctive physical characteristic of matter inside a white dwarf star is that it is

Accepted Answer

A)  composed only of protons, with electrostatic repulsion preventing stellar collapse. 
B)  of extremely high density compared with ordinary stellar matter. 
C)  composed only of neutrons. 
D)  composed only of electrons in a degenerate state. 
A)  composed only of protons, with electrostatic repulsion preventing stellar collapse. 
B)  of extremely high density compared with ordinary stellar matter. 
C)  composed only of neutrons. 
D)  composed only of electrons in a degenerate state.

The study of supernova 1987A and the study of the Sun have at least one aspect in common, namely

Which of these processes is NOT involved in the supernova explosion of a massive star?

The Sun will end its life by becoming a

The rings of material surrounding the SN 1987A remnant glow. In what region of the spectrum do they emit most of their radiation?

The main reason for the observed slowdown of many pulsars is

A Type Ia supernova is the

What is a hypernova?

When mass transfer in a binary system involves mass transferred to a white dwarf, the result is a nova. When the mass is transferred to a neutron star, the result is a(n)

After the material in the core of a massive star has been converted to iron by thermonuclear reactions, further energy can be released to heat the core only by

During its life, a massive star creates heavier and heavier elements in its core through thermonuclear fusion, leading up to silicon and iron. What is the fate of the iron that is created?

In the binary pulsar Hercules X-1 the periodic Doppler shift, once every 1.7 days, was discovered rather quickly. Even though the binary pulsar Centaurus X-3 was discovered earlier, its Doppler shift was discovered only much later. What might be a reason for this?

In the study of neutron stars, what is a "glitch"?

Measurements suggest that light first arrived at Earth from the Cassiopeia A supernova about 300 years ago and that this supernova is about 10,000 ly distant from Earth. When did the explosion actually occur?

A star at the tip of the asymptotic giant branch (AGB) is a

The event that follows the asymptotic giant branch (AGB) phase in the life of a low-mass star is

There is a mass limit for a star in the white-dwarf phase, the Chandrasekhar limit, beyond which the electron degeneracy pressure can no longer support the star against its own gravity. This limit is

Eta Carina is a

In terms of the evolutionary life of a star, at what stage is the Crab Nebula?

The source of the beams of electromagnetic radiation (including light in some cases) emitted by pulsars is

One distinctive physical characteristic of matter inside a white dwarf star is that it is

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

The study of supernova 1987A and the study of the Sun have at least one aspect in common, namely

Which of these processes is NOT involved in the supernova explosion of a massive star?

The Sun will end its life by becoming a

The rings of material surrounding the SN 1987A remnant glow. In what region of the spectrum do they emit most of their radiation?

The main reason for the observed slowdown of many pulsars is

A Type Ia supernova is the

What is a hypernova?

When mass transfer in a binary system involves mass transferred to a white dwarf, the result is a nova. When the mass is transferred to a neutron star, the result is a(n)

After the material in the core of a massive star has been converted to iron by thermonuclear reactions, further energy can be released to heat the core only by

During its life, a massive star creates heavier and heavier elements in its core through thermonuclear fusion, leading up to silicon and iron. What is the fate of the iron that is created?

In the binary pulsar Hercules X-1 the periodic Doppler shift, once every 1.7 days, was discovered rather quickly. Even though the binary pulsar Centaurus X-3 was discovered earlier, its Doppler shift was discovered only much later. What might be a reason for this?

In the study of neutron stars, what is a "glitch"?

Measurements suggest that light first arrived at Earth from the Cassiopeia A supernova about 300 years ago and that this supernova is about 10,000 ly distant from Earth. When did the explosion actually occur?

A star at the tip of the asymptotic giant branch (AGB) is a

The event that follows the asymptotic giant branch (AGB) phase in the life of a low-mass star is

There is a mass limit for a star in the white-dwarf phase, the Chandrasekhar limit, beyond which the electron degeneracy pressure can no longer support the star against its own gravity. This limit is

Eta Carina is a

In terms of the evolutionary life of a star, at what stage is the Crab Nebula?

The source of the beams of electromagnetic radiation (including light in some cases) emitted by pulsars is

One distinctive physical characteristic of matter inside a white dwarf star is that it is

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