Question 1

The energy-generation process inside a white dwarf is:

Accepted Answer

A)  the combining of protons and electrons to form neutrons within its core. 
B)  hydrogen fusion. 
C)  nonexistent-a white dwarf is simply cooling by radiating its original heat. 
D)  the helium flash-very efficient and rapid helium fusion. 
A)  the combining of protons and electrons to form neutrons within its core. 
B)  hydrogen fusion. 
C)  nonexistent-a white dwarf is simply cooling by radiating its original heat. 
D)  the helium flash-very efficient and rapid helium fusion.

Question 2

According to Einstein's theory of general relativity,if you watch a clock from a distant location as it is moved closer to a source of gravity,you will see the clock:

Accepted Answer

A)  maintain the same rate since time is unaffected by gravity. 
B)  change its rate if it is moving rapidly but maintain its standard rate if stationary in a gravity field. 
C)  slow down. 
D)  run faster. 
A)  maintain the same rate since time is unaffected by gravity. 
B)  change its rate if it is moving rapidly but maintain its standard rate if stationary in a gravity field. 
C)  slow down. 
D)  run faster.

Question 3

The shell of a planetary nebula is measured by the Doppler shift of emission lines to be expanding outward at a speed of 10⁴ m/s,while its radius is measured to be 1 ly,or about 10¹⁶ m.Roughly how long has the shell been expanding? (Hint: 1 year = 3.15 × 10⁷ sec.)

Accepted Answer

A)  30 years 
B)  30,000 years 
C)  30 million years 
D)  10¹² years 
A)  30 years 
B)  30,000 years 
C)  30 million years 
D)  10¹² years

Question 4

Which astronomical object is MOST closely associated with a pulsar?

Accepted Answer

A)  a red giant star 
B)  a neutron star 
C)  a black hole 
D)  a white dwarf star 
A)  a red giant star 
B)  a neutron star 
C)  a black hole 
D)  a white dwarf star

Question 5

Which is the CORRECT sequence for the end points of stellar evolution,in order of increasing mass?

Accepted Answer

A)  white dwarf, black hole, neutron star 
B)  white dwarf, neutron star, black hole 
C)  neutron star, black hole, white dwarf 
D)  black hole, neutron star, white dwarf 
A)  white dwarf, black hole, neutron star 
B)  white dwarf, neutron star, black hole 
C)  neutron star, black hole, white dwarf 
D)  black hole, neutron star, white dwarf

Question 6

For a massive star (e.g.,25 solar masses),core hydrogen fusion lasts for several million years.In contrast,core silicon fusion lasts for only about:

Accepted Answer

A)  1 minute. 
B)  several thousand years. 
C)  1 day. 
D)  1 year. 
A)  1 minute. 
B)  several thousand years. 
C)  1 day. 
D)  1 year.

Question 7

What is the name given to the type of planetary nebula in which a doughnut-shaped cloud of gas and dust in the plane of the equator channels the outflow in opposite directions toward the poles?

Accepted Answer

A)  dumbbell nebula 
B)  axial planetary nebula 
C)  doughnut planetary nebula 
D)  bipolar planetary nebula 
A)  dumbbell nebula 
B)  axial planetary nebula 
C)  doughnut planetary nebula 
D)  bipolar planetary nebula

Question 8

Which major astronomical event was apparently recorded faithfully by Chinese astronomers in the Sung Dynasty in a.d.1054?

Accepted Answer

A)  supernova explosion in the Milky Way Galaxy, visible even in daylight 
B)  total eclipse of the Sun over China 
C)  rare passage of the planet Venus across the face of the Sun, a solar transit 
D)  discovery of the planet Mercury 
A)  supernova explosion in the Milky Way Galaxy, visible even in daylight 
B)  total eclipse of the Sun over China 
C)  rare passage of the planet Venus across the face of the Sun, a solar transit 
D)  discovery of the planet Mercury

Question 9

How do Kerr black holes differ from Schwarzschild black holes?

Accepted Answer

A)  Kerr black holes have infinite mass; Schwarzschild black holes do not. 
B)  Kerr black holes have net electric charge; Schwarzschild black holes do not. 
C)  Kerr black holes have accretion disks; Schwarzschild black holes do not. 
D)  Kerr black holes rotate; Schwarzschild black holes do not. 
A)  Kerr black holes have infinite mass; Schwarzschild black holes do not. 
B)  Kerr black holes have net electric charge; Schwarzschild black holes do not. 
C)  Kerr black holes have accretion disks; Schwarzschild black holes do not. 
D)  Kerr black holes rotate; Schwarzschild black holes do not.

Question 10

Suppose you are in a spaceship traveling toward Earth at 95% of the speed of light.Compared with when your ship was at rest on Mars,what length do you measure for your spaceship?

Accepted Answer

A)  You cannot tell; your life processes have slowed down too much for you to measure the length. 
B)  the same 
C)  shorter 
D)  longer 
A)  You cannot tell; your life processes have slowed down too much for you to measure the length. 
B)  the same 
C)  shorter 
D)  longer

Question 11

Most supernova remnants can be observed only at nonvisible wavelengths.Explain.

Accepted Answer

A)  Supernova remnants are too cool to produce radiation at visible wavelengths. 
B)  Supernova remnants are too hot to produce radiation at visible wavelengths. 
C)  Visible wavelengths are produced by supernova remnants but they are blocked by the interstellar medium. 
D)  All the visible wavelengths are Doppler shifted to infrared because all the supernova remnants are moving away from us at high speeds. 
A)  Supernova remnants are too cool to produce radiation at visible wavelengths. 
B)  Supernova remnants are too hot to produce radiation at visible wavelengths. 
C)  Visible wavelengths are produced by supernova remnants but they are blocked by the interstellar medium. 
D)  All the visible wavelengths are Doppler shifted to infrared because all the supernova remnants are moving away from us at high speeds.

Question 12

The light from the MOST recent supernova that was visible to the unaided eye arrived at Earth in a.d.:

Accepted Answer

A)  1604. 
B)  1054. 
C)  1987. 
D)  1572. 
A)  1604. 
B)  1054. 
C)  1987. 
D)  1572.

Question 13

What appears to happen to a clock as it approaches and reaches the event horizon around a black hole when viewed by a remote observer?

Accepted Answer

A)  Time appears to pass at a much faster rate, becoming infinitely fast at the event horizon. 
B)  Time appears to slow down and stop. 
C)  Time speeds up because of the intensified gravitational field. 
D)  Time ticks uniformly since nothing changes the progress of time. 
A)  Time appears to pass at a much faster rate, becoming infinitely fast at the event horizon. 
B)  Time appears to slow down and stop. 
C)  Time speeds up because of the intensified gravitational field. 
D)  Time ticks uniformly since nothing changes the progress of time.

Question 14

In principle,if you were in the vicinity of a Schwarzschild black hole,how could you measure its mass?

Accepted Answer

A)  Put a satellite in orbit around it and measure its period. 
B)  Measure the gravitational redshift from its radiation. 
C)  Use charged particles to measure the strength of its magnetic field. 
D)  Measure the speed necessary to pass through the ergoregions and emerge. 
A)  Put a satellite in orbit around it and measure its period. 
B)  Measure the gravitational redshift from its radiation. 
C)  Use charged particles to measure the strength of its magnetic field. 
D)  Measure the speed necessary to pass through the ergoregions and emerge.

Question 15

Where would you look for a pulsar among the following locations in the universe?

Accepted Answer

A)  at the center of our Galaxy 
B)  in the Crab Nebula 
C)  in the Orion Nebula 
D)  in the middle of the Sun 
A)  at the center of our Galaxy 
B)  in the Crab Nebula 
C)  in the Orion Nebula 
D)  in the middle of the Sun

Question 16

What are the glitches occasionally observed by astronomers studying pulsars?

Accepted Answer

A)  secondary pulses of radiation occasionally interspersed with the primary pulses 
B)  clumps of denser material in the jets of particles emitted along the magnetic poles 
C)  sudden flares caused by matter falling onto the surface of a neutron star 
D)  sudden changes in a pulsar's rotation rate 
A)  secondary pulses of radiation occasionally interspersed with the primary pulses 
B)  clumps of denser material in the jets of particles emitted along the magnetic poles 
C)  sudden flares caused by matter falling onto the surface of a neutron star 
D)  sudden changes in a pulsar's rotation rate

Question 17

What percentage of all matter ejected into the interstellar medium in the Milky Way Galaxy each year by stars is contributed by planetary nebulae?

Accepted Answer

A)  less than 1% 
B)  about 50% 
C)  between 10 and 20% 
D)  almost 100% 
A)  less than 1% 
B)  about 50% 
C)  between 10 and 20% 
D)  almost 100%

Question 18

According to general relativity,why does Earth orbit the Sun?

Accepted Answer

A)  Matter contains quarks, and Earth and the Sun attract each other with the "color force" between their quarks. 
B)  Space around the Sun is curved, and Earth follows a geodesic in this curved space. 
C)  The Sun exerts a gravitational force on Earth across empty space. 
D)  Earth and the Sun are continually exchanging photons of light in a way that holds Earth in orbit. 
A)  Matter contains quarks, and Earth and the Sun attract each other with the "color force" between their quarks. 
B)  Space around the Sun is curved, and Earth follows a geodesic in this curved space. 
C)  The Sun exerts a gravitational force on Earth across empty space. 
D)  Earth and the Sun are continually exchanging photons of light in a way that holds Earth in orbit.

Question 19

A white dwarf,as it evolves,undergoes which change?

Accepted Answer

A)  Its temperature remains constant, but its radius and therefore its luminosity decrease. 
B)  Luminosity and size decrease, while its temperature remains constant. 
C)  It shrinks in size, the resulting release of gravitational energy keeping both luminosity and temperature constant. 
D)  Luminosity and temperature decrease. 
A)  Its temperature remains constant, but its radius and therefore its luminosity decrease. 
B)  Luminosity and size decrease, while its temperature remains constant. 
C)  It shrinks in size, the resulting release of gravitational energy keeping both luminosity and temperature constant. 
D)  Luminosity and temperature decrease.

Question 20

In astronomical terms,planetary nebulae are:

Accepted Answer

A)  very long-lived objects, having been in existence since just after the Big Bang at the beginning of the universe. 
B)  relatively short-lived, existing around the central white dwarf star for millions of years before slowly spreading into space. 
C)  relatively long-lived since they form when the original stars form and remain as slowly rotating shells for the whole of their lifetimes of several billion years. 
D)  very short-lived, with lifetimes of about 50,000 years. 
A)  very long-lived objects, having been in existence since just after the Big Bang at the beginning of the universe. 
B)  relatively short-lived, existing around the central white dwarf star for millions of years before slowly spreading into space. 
C)  relatively long-lived since they form when the original stars form and remain as slowly rotating shells for the whole of their lifetimes of several billion years. 
D)  very short-lived, with lifetimes of about 50,000 years.

The energy-generation process inside a white dwarf is:

According to Einstein's theory of general relativity,if you watch a clock from a distant location as it is moved closer to a source of gravity,you will see the clock:

The shell of a planetary nebula is measured by the Doppler shift of emission lines to be expanding outward at a speed of 10⁴ m/s,while its radius is measured to be 1 ly,or about 10¹⁶ m.Roughly how long has the shell been expanding? (Hint: 1 year = 3.15 × 10⁷ sec.)

Which astronomical object is MOST closely associated with a pulsar?

Which is the CORRECT sequence for the end points of stellar evolution,in order of increasing mass?

For a massive star (e.g.,25 solar masses),core hydrogen fusion lasts for several million years.In contrast,core silicon fusion lasts for only about:

What is the name given to the type of planetary nebula in which a doughnut-shaped cloud of gas and dust in the plane of the equator channels the outflow in opposite directions toward the poles?

Which major astronomical event was apparently recorded faithfully by Chinese astronomers in the Sung Dynasty in a.d.1054?

How do Kerr black holes differ from Schwarzschild black holes?

Suppose you are in a spaceship traveling toward Earth at 95% of the speed of light.Compared with when your ship was at rest on Mars,what length do you measure for your spaceship?

Most supernova remnants can be observed only at nonvisible wavelengths.Explain.

The light from the MOST recent supernova that was visible to the unaided eye arrived at Earth in a.d.:

What appears to happen to a clock as it approaches and reaches the event horizon around a black hole when viewed by a remote observer?

In principle,if you were in the vicinity of a Schwarzschild black hole,how could you measure its mass?

Where would you look for a pulsar among the following locations in the universe?

What are the glitches occasionally observed by astronomers studying pulsars?

What percentage of all matter ejected into the interstellar medium in the Milky Way Galaxy each year by stars is contributed by planetary nebulae?

According to general relativity,why does Earth orbit the Sun?

A white dwarf,as it evolves,undergoes which change?

In astronomical terms,planetary nebulae are:

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 energy-generation process inside a white dwarf is:

According to Einstein's theory of general relativity,if you watch a clock from a distant location as it is moved closer to a source of gravity,you will see the clock:

The shell of a planetary nebula is measured by the Doppler shift of emission lines to be expanding outward at a speed of 10⁴ m/s,while its radius is measured to be 1 ly,or about 10¹⁶ m.Roughly how long has the shell been expanding? (Hint: 1 year = 3.15 × 10⁷ sec.)

Which astronomical object is MOST closely associated with a pulsar?

Which is the CORRECT sequence for the end points of stellar evolution,in order of increasing mass?

For a massive star (e.g.,25 solar masses),core hydrogen fusion lasts for several million years.In contrast,core silicon fusion lasts for only about:

What is the name given to the type of planetary nebula in which a doughnut-shaped cloud of gas and dust in the plane of the equator channels the outflow in opposite directions toward the poles?

Which major astronomical event was apparently recorded faithfully by Chinese astronomers in the Sung Dynasty in a.d.1054?

How do Kerr black holes differ from Schwarzschild black holes?

Suppose you are in a spaceship traveling toward Earth at 95% of the speed of light.Compared with when your ship was at rest on Mars,what length do you measure for your spaceship?

Most supernova remnants can be observed only at nonvisible wavelengths.Explain.

The light from the MOST recent supernova that was visible to the unaided eye arrived at Earth in a.d.:

What appears to happen to a clock as it approaches and reaches the event horizon around a black hole when viewed by a remote observer?

In principle,if you were in the vicinity of a Schwarzschild black hole,how could you measure its mass?

Where would you look for a pulsar among the following locations in the universe?

What are the glitches occasionally observed by astronomers studying pulsars?

What percentage of all matter ejected into the interstellar medium in the Milky Way Galaxy each year by stars is contributed by planetary nebulae?

According to general relativity,why does Earth orbit the Sun?

A white dwarf,as it evolves,undergoes which change?

In astronomical terms,planetary nebulae are:

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