Question 1

A photon is emitted from the surface of a massive star.As it moves away from the star it experiences all of the following EXCEPT ONE.Which is the exception?

Accepted Answer

A)  The wavelength will increase. 
B)  The frequency will decrease. 
C)  The speed will be reduced. 
D)  The energy will be reduced. 
A)  The wavelength will increase. 
B)  The frequency will decrease. 
C)  The speed will be reduced. 
D)  The energy will be reduced. C

Question 2

Efforts to relate gamma-ray bursts with specific sources has had what results so far?

Accepted Answer

A)  Gamma-ray bursters always occur in the depths of space, far from any galactic or other obvious source. 
B)  Gamma-ray bursters, including those observed in the Milky Way Galaxy, always occur in the centers of galaxies. 
C)  Gamma-ray bursters appear to occur in galaxies but not at the centers of galaxies. 
D)  Gamma-ray bursters occur in globular clusters, well away from the main regions in the host galaxy. 
A)  Gamma-ray bursters always occur in the depths of space, far from any galactic or other obvious source. 
B)  Gamma-ray bursters, including those observed in the Milky Way Galaxy, always occur in the centers of galaxies. 
C)  Gamma-ray bursters appear to occur in galaxies but not at the centers of galaxies. 
D)  Gamma-ray bursters occur in globular clusters, well away from the main regions in the host galaxy. C

Question 3

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: 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: remnant of a star explosion or supernova D

Question 4

A light wave is emitted from the accretion disk surrounding a black hole and moves toward the hole and away from an observer.This observer will see:

Accepted Answer

A)  the beam of light moving faster than c as it accelerates toward the hole. 
B)  the beam of light slow down and stop as it reaches the event horizon. 
C)  that the wavelength of the light is gravitationally blueshifted and Doppler redshifted, and the two effects just cancel as the light reaches the event horizon. 
D)  that the wavelength of the light is gravitationally blueshifted as it falls toward the event horizon. 
A)  the beam of light moving faster than c as it accelerates toward the hole. 
B)  the beam of light slow down and stop as it reaches the event horizon. 
C)  that the wavelength of the light is gravitationally blueshifted and Doppler redshifted, and the two effects just cancel as the light reaches the event horizon. 
D)  that the wavelength of the light is gravitationally blueshifted as it falls toward the event horizon.

Question 5

The main product of silicon fusion reactions in the core of a massive star is:

Accepted Answer

A)  iron. 
B)  magnesium. 
C)  carbon. 
D)  helium. 
A)  iron. 
B)  magnesium. 
C)  carbon. 
D)  helium.

Question 6

Which statement about the evaporation of black holes is CORRECT?

Accepted Answer

A)  The rate at which a black hole evaporates is lower for a higher-mass black hole. 
B)  The rate at which a black hole evaporates is higher for a higher-mass black hole. 
C)  Black holes do not evaporate. 
D)  The rate at which a black hole evaporates is independent of the mass of the black hole. 
A)  The rate at which a black hole evaporates is lower for a higher-mass black hole. 
B)  The rate at which a black hole evaporates is higher for a higher-mass black hole. 
C)  Black holes do not evaporate. 
D)  The rate at which a black hole evaporates is independent of the mass of the black hole.

Question 7

Some objects in the Milky Way Galaxy are observed to eject two oppositely directed jets of X-rays.These X-ray jets are believed to be from the accelerations of:

Accepted Answer

A)  energetic, charged particles ejected along the magnetic axes of a rotating neutron star. 
B)  the material squirted out along the rotation axis of an accretion disk around a neutron star in a binary star system. 
C)  the material transferred onto the surface of a white dwarf in a binary star system, then subsequently blasted into space by runaway thermonuclear fusion reactions. 
D)  the material expelled from the far side of the companion star in a binary system, repelled by magnetic interaction with the pulsar. 
A)  energetic, charged particles ejected along the magnetic axes of a rotating neutron star. 
B)  the material squirted out along the rotation axis of an accretion disk around a neutron star in a binary star system. 
C)  the material transferred onto the surface of a white dwarf in a binary star system, then subsequently blasted into space by runaway thermonuclear fusion reactions. 
D)  the material expelled from the far side of the companion star in a binary system, repelled by magnetic interaction with the pulsar.

Question 8

What is a pulsar?

Accepted Answer

A)  very hot material orbiting a black hole 
B)  a Cepheid variable star with a period of a few days 
C)  a pulsating white dwarf, fluctuating rapidly in brightness 
D)  a rapidly rotating neutron star, producing beams of radio energy and occasionally of X-rays and visible light 
A)  very hot material orbiting a black hole 
B)  a Cepheid variable star with a period of a few days 
C)  a pulsating white dwarf, fluctuating rapidly in brightness 
D)  a rapidly rotating neutron star, producing beams of radio energy and occasionally of X-rays and visible light

Question 9

The enormous densities that develop during a supernova collapse do not appear to be sufficient to form the heaviest elements.Where can we find the even greater pressures that produced these elements?

Accepted Answer

A)  the Big Bang 
B)  collisions of neutron stars 
C)  magnetars 
D)  quasars 
A)  the Big Bang 
B)  collisions of neutron stars 
C)  magnetars 
D)  quasars

Question 10

Gas jets have often formed perpendicular to the plane of the accretion disk around a black hole or a neutron star.What propels the gas away from the hole or star?

Accepted Answer

A)  magnetic forces from the object's strong magnetic field 
B)  conservation of momentum since the outgoing particles are pair-produced as virtual particles near the object 
C)  enormous pressure of the compressed infalling gas of the accretion disk 
D)  strong curvature of spacetime near the object 
A)  magnetic forces from the object's strong magnetic field 
B)  conservation of momentum since the outgoing particles are pair-produced as virtual particles near the object 
C)  enormous pressure of the compressed infalling gas of the accretion disk 
D)  strong curvature of spacetime near the object

Question 11

Can a white dwarf explode?

Accepted Answer

A)  Yes, but only if another star collides with it; stars are so far apart in space that this is unlikely ever to have happened in our Galaxy. 
B)  Yes, but only if it is in a binary star system. 
C)  Yes, but only if nuclear reactions in the white dwarf core reach the stage of silicon fusion, producing iron. 
D)  No. White dwarfs are held up by electron degeneracy pressure, and this configuration is stable against collapse or explosion. 
A)  Yes, but only if another star collides with it; stars are so far apart in space that this is unlikely ever to have happened in our Galaxy. 
B)  Yes, but only if it is in a binary star system. 
C)  Yes, but only if nuclear reactions in the white dwarf core reach the stage of silicon fusion, producing iron. 
D)  No. White dwarfs are held up by electron degeneracy pressure, and this configuration is stable against collapse or explosion.

Question 12

The characteristics of a red supergiant star are the brightness of _____ and a diameter of _____.

Accepted Answer

A)  10,000 Suns; about Mars' orbit 
B)  the Sun; Mercury's orbit 
C)  about 1 million Suns; the whole solar system 
D)  about 10,000 Suns; 1/10 that of the Sun 
A)  10,000 Suns; about Mars' orbit 
B)  the Sun; Mercury's orbit 
C)  about 1 million Suns; the whole solar system 
D)  about 10,000 Suns; 1/10 that of the Sun

Question 13

The first pulsar was discovered by:

Accepted Answer

A)  Albert Einstein in 1905. 
B)  Galileo Galilei in 1610. 
C)  the Astronomer Royal in Newton's time, Sir Edmund Halley, in 1606. 
D)  an English graduate student, Jocelyn Bell, in 1967. 
A)  Albert Einstein in 1905. 
B)  Galileo Galilei in 1610. 
C)  the Astronomer Royal in Newton's time, Sir Edmund Halley, in 1606. 
D)  an English graduate student, Jocelyn Bell, in 1967.

Question 14

What is a superstring?

Accepted Answer

A)  a new kind of force postulated to keep a companion binary star from falling into a black hole 
B)  a line of material along which the jets shoot out from neutron stars and black holes 
C)  a new theory of physics that is intended to describe what happens inside the event horizon of a black hole 
D)  a force that holds quarks together in a quark star 
A)  a new kind of force postulated to keep a companion binary star from falling into a black hole 
B)  a line of material along which the jets shoot out from neutron stars and black holes 
C)  a new theory of physics that is intended to describe what happens inside the event horizon of a black hole 
D)  a force that holds quarks together in a quark star

Question 15

White dwarfs are supported from gravitational collapse by:

Accepted Answer

A)  centrifugal force due to rapid rotation. 
B)  degenerate-electron pressure. 
C)  nuclear fusion reactions in their cores. 
D)  nuclear fusion reactions in a shell around the core. 
A)  centrifugal force due to rapid rotation. 
B)  degenerate-electron pressure. 
C)  nuclear fusion reactions in their cores. 
D)  nuclear fusion reactions in a shell around the core.

Question 16

Which statement CORRECTLY describes cosmic censorship?

Accepted Answer

A)  Black holes cannot have magnetic fields. 
B)  All properties of the matter inside a black hole are hidden by the event horizon, except for the total mass of the matter. 
C)  The amount of mass in a black hole can never be measured. 
D)  Nothing can leave a local region of space that contains a singularity. 
A)  Black holes cannot have magnetic fields. 
B)  All properties of the matter inside a black hole are hidden by the event horizon, except for the total mass of the matter. 
C)  The amount of mass in a black hole can never be measured. 
D)  Nothing can leave a local region of space that contains a singularity.

Question 17

A high-mass star near the end of its life undergoes successive cycles of energy generation in its core in which gravitational collapse increases the temperature to the point where a new nuclear fusion cycle generates sufficient energy to stop the collapse.This process does not work beyond the silicon-fusion cycle that produces iron.Explain.

Accepted Answer

A)  The pressure from high-energy photons and neutrinos at the very high core temperatures reached at this stage of development is finally sufficient to halt the collapse. 
B)  Electrostatic forces between the highly charged iron nuclei are sufficient to overcome the collapse and stabilize the stellar core. 
C)  Fusion of iron nuclei into heavier nuclei requires energy rather than producing excess energy and therefore will not produce the additional gas pressure to halt the collapse. 
D)  Iron nuclei are so large that they occupy all remaining space, so the collapse cannot continue. 
A)  The pressure from high-energy photons and neutrinos at the very high core temperatures reached at this stage of development is finally sufficient to halt the collapse. 
B)  Electrostatic forces between the highly charged iron nuclei are sufficient to overcome the collapse and stabilize the stellar core. 
C)  Fusion of iron nuclei into heavier nuclei requires energy rather than producing excess energy and therefore will not produce the additional gas pressure to halt the collapse. 
D)  Iron nuclei are so large that they occupy all remaining space, so the collapse cannot continue.

Question 18

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 19

You are on Mars standing on the gangplank of your spaceship when you see an identical spaceship go past Mars at 90% of the speed of light.When you look closely at this spaceship,how does it compare with your own spaceship?

Accepted Answer

A)  The moving spaceship appears to be shorter than yours, and time on it appears to move more slowly than on your ship. 
B)  The moving spaceship appears to be shorter than yours, and time on it appears to move more quickly than on your ship. 
C)  The moving spaceship appears to be longer than yours, and time on it appears to move more quickly than on your ship. 
D)  The moving spaceship appears to be longer than yours, and time on it appears to move more slowly than on your ship. 
A)  The moving spaceship appears to be shorter than yours, and time on it appears to move more slowly than on your ship. 
B)  The moving spaceship appears to be shorter than yours, and time on it appears to move more quickly than on your ship. 
C)  The moving spaceship appears to be longer than yours, and time on it appears to move more quickly than on your ship. 
D)  The moving spaceship appears to be longer than yours, and time on it appears to move more slowly than on your ship.

Question 20

Consider a group of stars with masses up to eight times the mass of the Sun.Stars of which masses will pass along the horizontal branch?

Accepted Answer

A)  less than 0.4 M 
B)  0.4 M to 2 M only 
C)  2 M to 8 M only 
D)  all stars 0.4 M to 8 M 
A)  less than 0.4 M 
B)  0.4 M to 2 M only 
C)  2 M to 8 M only 
D)  all stars 0.4 M to 8 M

A photon is emitted from the surface of a massive star.As it moves away from the star it experiences all of the following EXCEPT ONE.Which is the exception?

Efforts to relate gamma-ray bursts with specific sources has had what results so far?

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

A light wave is emitted from the accretion disk surrounding a black hole and moves toward the hole and away from an observer.This observer will see:

The main product of silicon fusion reactions in the core of a massive star is:

Which statement about the evaporation of black holes is CORRECT?

Some objects in the Milky Way Galaxy are observed to eject two oppositely directed jets of X-rays.These X-ray jets are believed to be from the accelerations of:

What is a pulsar?

The enormous densities that develop during a supernova collapse do not appear to be sufficient to form the heaviest elements.Where can we find the even greater pressures that produced these elements?

Gas jets have often formed perpendicular to the plane of the accretion disk around a black hole or a neutron star.What propels the gas away from the hole or star?

Can a white dwarf explode?

The characteristics of a red supergiant star are the brightness of _ and a diameter of _.

The first pulsar was discovered by:

What is a superstring?

White dwarfs are supported from gravitational collapse by:

Which statement CORRECTLY describes cosmic censorship?

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?

You are on Mars standing on the gangplank of your spaceship when you see an identical spaceship go past Mars at 90% of the speed of light.When you look closely at this spaceship,how does it compare with your own spaceship?

Consider a group of stars with masses up to eight times the mass of the Sun.Stars of which masses will pass along the horizontal branch?

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

A photon is emitted from the surface of a massive star.As it moves away from the star it experiences all of the following EXCEPT ONE.Which is the exception?

Efforts to relate gamma-ray bursts with specific sources has had what results so far?

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

A light wave is emitted from the accretion disk surrounding a black hole and moves toward the hole and away from an observer.This observer will see:

The main product of silicon fusion reactions in the core of a massive star is:

Which statement about the evaporation of black holes is CORRECT?

Some objects in the Milky Way Galaxy are observed to eject two oppositely directed jets of X-rays.These X-ray jets are believed to be from the accelerations of:

What is a pulsar?

The enormous densities that develop during a supernova collapse do not appear to be sufficient to form the heaviest elements.Where can we find the even greater pressures that produced these elements?

Gas jets have often formed perpendicular to the plane of the accretion disk around a black hole or a neutron star.What propels the gas away from the hole or star?

Can a white dwarf explode?

The characteristics of a red supergiant star are the brightness of _____ and a diameter of _____.

The first pulsar was discovered by:

What is a superstring?

White dwarfs are supported from gravitational collapse by:

Which statement CORRECTLY describes cosmic censorship?

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?

You are on Mars standing on the gangplank of your spaceship when you see an identical spaceship go past Mars at 90% of the speed of light.When you look closely at this spaceship,how does it compare with your own spaceship?

Consider a group of stars with masses up to eight times the mass of the Sun.Stars of which masses will pass along the horizontal branch?

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

The characteristics of a red supergiant star are the brightness of _ and a diameter of _.