Question 1

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 2

The main component of primary cosmic rays is:

Accepted Answer

A)  protons. 
B)  gamma rays. 
C)  electrons. 
D)  nuclei of heavy elements such as carbon and iron. 
A)  protons. 
B)  gamma rays. 
C)  electrons. 
D)  nuclei of heavy elements such as carbon and iron.

Question 3

The Scorpius-Centaurus OB association is predicted to have produced a supernova about 2 million years ago.What led to this prediction?

Accepted Answer

A)  A supernova remnant with the appropriate location and age was found. 
B)  O and B stars are massive stars, many of them over 25 solar masses, and they would supernova. 
C)  In a close association, collisions between stars are expected, and collisions would raise the mass to the supernova range. 
D)  Shock waves from the direction of Scorpius-Centaurus still pass by Earth at frequent intervals. 
A)  A supernova remnant with the appropriate location and age was found. 
B)  O and B stars are massive stars, many of them over 25 solar masses, and they would supernova. 
C)  In a close association, collisions between stars are expected, and collisions would raise the mass to the supernova range. 
D)  Shock waves from the direction of Scorpius-Centaurus still pass by Earth at frequent intervals.

Question 4

What is the cause of millisecond pulsars?

Accepted Answer

A)  As a pulsar cools, it collapses further. This causes its rotation rate to increase. 
B)  Pulsars in binary systems can draw mass from the binary companion. This mass, impacting the pulsar's surface, causes its rotation rate to increase. 
C)  The jets which radiate energy away from a pulsar cause it to become smaller and to rotate faster. 
D)  The rotation period for most pulsars is actually less than a millisecond. So the natural slowing as it loses energy moves it into the millisecond range. 
A)  As a pulsar cools, it collapses further. This causes its rotation rate to increase. 
B)  Pulsars in binary systems can draw mass from the binary companion. This mass, impacting the pulsar's surface, causes its rotation rate to increase. 
C)  The jets which radiate energy away from a pulsar cause it to become smaller and to rotate faster. 
D)  The rotation period for most pulsars is actually less than a millisecond. So the natural slowing as it loses energy moves it into the millisecond range.

Question 5

Pulsars emitting very regular radio and sometimes visible light pulses are what type of object?

Accepted Answer

A)  black holes, with material falling regularly into them 
B)  pulsating variable stars 
C)  rapidly rotating neutron stars 
D)  rapidly rotating binary star systems in which the stars undergo regular eclipses as seen from Earth 
A)  black holes, with material falling regularly into them 
B)  pulsating variable stars 
C)  rapidly rotating neutron stars 
D)  rapidly rotating binary star systems in which the stars undergo regular eclipses as seen from Earth

Question 6

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 7

A planetary nebula is:

Accepted Answer

A)  a shell of ejected gases. 
B)  the formation stages of planets around stars. 
C)  a gas cloud surrounding a planet after its formation. 
D)  the spherical cloud of gas produced by a supernova explosion. 
A)  a shell of ejected gases. 
B)  the formation stages of planets around stars. 
C)  a gas cloud surrounding a planet after its formation. 
D)  the spherical cloud of gas produced by a supernova explosion.

Question 8

An old high-mass star can have a number of shells (hydrogen,helium,carbon,neon,oxygen,silicon)plus an iron core.Fusion generally takes place everywhere EXCEPT the:

Accepted Answer

A)  hydrogen shell. 
B)  helium shell. 
C)  silicon shell. 
D)  iron core. 
A)  hydrogen shell. 
B)  helium shell. 
C)  silicon shell. 
D)  iron core.

Question 9

In the context of black holes,the word ergosphere names the:

Accepted Answer

A)  entire region inside the event horizon. 
B)  region just outside the event horizon of a rotating black hole where it is impossible for anything to remain at rest. 
C)  entire universe outside the black hole. 
D)  region occupied by the accretion disk where matter from a companion star collects around a black hole. 
A)  entire region inside the event horizon. 
B)  region just outside the event horizon of a rotating black hole where it is impossible for anything to remain at rest. 
C)  entire universe outside the black hole. 
D)  region occupied by the accretion disk where matter from a companion star collects around a black hole.

Question 10

What name is given to any black hole that might have been created in the Big Bang at the beginning of the universe?

Accepted Answer

A)  supermassive black hole 
B)  Schwarzschild black hole 
C)  Kerr black hole 
D)  primordial black hole 
A)  supermassive black hole 
B)  Schwarzschild black hole 
C)  Kerr black hole 
D)  primordial black hole

Question 11

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 12

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.

Question 13

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 14

Where does the energy come from to produce the gravitational waves that are emitted when a massive star collapses to become a black hole?

Accepted Answer

A)  E = mc². Some of the star's matter disappears. 
B)  from the kinetic energy of the outward motion of the explosion 
C)  from the magnetic fields of the star 
D)  from the energy lost in the gravitational redshift 
A)  E = mc². Some of the star's matter disappears. 
B)  from the kinetic energy of the outward motion of the explosion 
C)  from the magnetic fields of the star 
D)  from the energy lost in the gravitational redshift

Question 15

Your spaceship is passing your friend's ship,which is traveling in the opposite direction.You measure his ship to be moving at 60% of the speed of light relative to you.Later you ask your friend what he measured your speed to be at that time relative to him.What is his answer?

Accepted Answer

A)  0.6 c 
B)  less than 0.6 c 
C)  more than 0.6 c but less than c 
D)  more than c 
A)  0.6 c 
B)  less than 0.6 c 
C)  more than 0.6 c but less than c 
D)  more than c

Question 16

Where would you look for a supermassive black hole?

Accepted Answer

A)  in the center of a galaxy 
B)  at the center of the universe 
C)  orbiting a normal star in the Milky Way Galaxy 
D)  at the center of a supernova remnant 
A)  in the center of a galaxy 
B)  at the center of the universe 
C)  orbiting a normal star in the Milky Way Galaxy 
D)  at the center of a supernova remnant

Question 17

What is a Schwarzschild black hole?

Accepted Answer

A)  a supermassive black hole 
B)  an uncharged black hole 
C)  a black hole that fills its Schwarzschild radius with matter 
D)  a nonrotating black hole 
A)  a supermassive black hole 
B)  an uncharged black hole 
C)  a black hole that fills its Schwarzschild radius with matter 
D)  a nonrotating black hole

Question 18

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

Accepted Answer

A)  its size or radius slowly increases as it cools until it ends up as a red giant star. 
B)  its size or radius remains constant as it cools and becomes less luminous. 
C)  it heats up as it shrinks because of the release of gravitational energy, ending up as a very hot but very small star. 
D)  it shrinks as it cools, eventually becoming a cold, black hole in space. 
A)  its size or radius slowly increases as it cools until it ends up as a red giant star. 
B)  its size or radius remains constant as it cools and becomes less luminous. 
C)  it heats up as it shrinks because of the release of gravitational energy, ending up as a very hot but very small star. 
D)  it shrinks as it cools, eventually becoming a cold, black hole in space.

Question 19

At which phase of its evolutionary life is a white dwarf?

Accepted Answer

A)  post-supernova phase, the central remnant of the explosion 
B)  just at main-sequence, or hydrogen-fusion, phase 
C)  very late for small-mass stars, in the dying phase 
D)  in its early phases, soon after formation 
A)  post-supernova phase, the central remnant of the explosion 
B)  just at main-sequence, or hydrogen-fusion, phase 
C)  very late for small-mass stars, in the dying phase 
D)  in its early phases, soon after formation

Question 20

Suppose you detect a massive object that displays jets of material shooting out of opposite sides.This object is probably NOT a:

Accepted Answer

A)  solitary black hole. 
B)  black hole in a binary system. 
C)  neutron star in a binary system. 
D)  supermassive black hole. 
A)  solitary black hole. 
B)  black hole in a binary system. 
C)  neutron star in a binary system. 
D)  supermassive black hole.

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:

The main component of primary cosmic rays is:

The Scorpius-Centaurus OB association is predicted to have produced a supernova about 2 million years ago.What led to this prediction?

What is the cause of millisecond pulsars?

Pulsars emitting very regular radio and sometimes visible light pulses are what type of object?

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):

A planetary nebula is:

An old high-mass star can have a number of shells (hydrogen,helium,carbon,neon,oxygen,silicon)plus an iron core.Fusion generally takes place everywhere EXCEPT the:

In the context of black holes,the word ergosphere names the:

What name is given to any black hole that might have been created in the Big Bang at the beginning of the universe?

The Sun will end its life by becoming a:

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

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

Where does the energy come from to produce the gravitational waves that are emitted when a massive star collapses to become a black hole?

Your spaceship is passing your friend's ship,which is traveling in the opposite direction.You measure his ship to be moving at 60% of the speed of light relative to you.Later you ask your friend what he measured your speed to be at that time relative to him.What is his answer?

Where would you look for a supermassive black hole?

What is a Schwarzschild black hole?

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

At which phase of its evolutionary life is a white dwarf?

Suppose you detect a massive object that displays jets of material shooting out of opposite sides.This object is probably NOT a:

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

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:

The main component of primary cosmic rays is:

The Scorpius-Centaurus OB association is predicted to have produced a supernova about 2 million years ago.What led to this prediction?

What is the cause of millisecond pulsars?

Pulsars emitting very regular radio and sometimes visible light pulses are what type of object?

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):

A planetary nebula is:

An old high-mass star can have a number of shells (hydrogen,helium,carbon,neon,oxygen,silicon)plus an iron core.Fusion generally takes place everywhere EXCEPT the:

In the context of black holes,the word ergosphere names the:

What name is given to any black hole that might have been created in the Big Bang at the beginning of the universe?

The Sun will end its life by becoming a:

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

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

Where does the energy come from to produce the gravitational waves that are emitted when a massive star collapses to become a black hole?

Your spaceship is passing your friend's ship,which is traveling in the opposite direction.You measure his ship to be moving at 60% of the speed of light relative to you.Later you ask your friend what he measured your speed to be at that time relative to him.What is his answer?

Where would you look for a supermassive black hole?

What is a Schwarzschild black hole?

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

At which phase of its evolutionary life is a white dwarf?

Suppose you detect a massive object that displays jets of material shooting out of opposite sides.This object is probably NOT a:

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