Question 1

Are crystalline stars or crystalline remnants of stars possible? Why or why not?

Accepted Answer

A)  No. Stars and stellar remnants are too hot to crystallize. 
B)  Yes. They are the likely outcome of the cooling of a white dwarf. 
C)  No. The forces needed to crystallize a star would actually cause the star to collapse gravitationally into a black hole. 
D)  Yes. They are the likely outcome of the creation of iron in the core of a massive star. 
A)  No. Stars and stellar remnants are too hot to crystallize. 
B)  Yes. They are the likely outcome of the cooling of a white dwarf. 
C)  No. The forces needed to crystallize a star would actually cause the star to collapse gravitationally into a black hole. 
D)  Yes. They are the likely outcome of the creation of iron in the core of a massive star.

Question 2

At which location will Newton's laws of motion be inadequate in describing precisely the motions of objects?

Accepted Answer

A)  in the Space Shuttle, moving around Earth at a speed of about 8 km/sec 
B)  at the center of Earth 
C)  inside an artillery shell as it accelerates inside the gun barrel 
D)  inside the orbit of Mercury 
A)  in the Space Shuttle, moving around Earth at a speed of about 8 km/sec 
B)  at the center of Earth 
C)  inside an artillery shell as it accelerates inside the gun barrel 
D)  inside the orbit of Mercury

Question 3

Supernovae are detected:

Accepted Answer

A)  in both the Milky Way Galaxy and other galaxies. 
B)  only at X-ray wavelengths. 
C)  only in elliptical galaxies, never in spirals. 
D)  only in the Milky Way Galaxy. 
A)  in both the Milky Way Galaxy and other galaxies. 
B)  only at X-ray wavelengths. 
C)  only in elliptical galaxies, never in spirals. 
D)  only in the Milky Way Galaxy.

Question 4

A laborer repairing the clock tower on a space station orbiting a black hole accidentally drops the clock in such a way that it accelerates toward the black hole.What does the worker see while watching the clock?

Accepted Answer

A)  The hands of the clock keep normal time since time is absolute and the same everywhere. 
B)  The hands of the clock move slower and slower until they and the clock itself stop at the event horizon. 
C)  As the clock nears the event horizon, the hands begin to move randomly as time becomes jumbled near the black hole. 
D)  The hands of the clock move faster and faster until the clock plunges through the event horizon. 
A)  The hands of the clock keep normal time since time is absolute and the same everywhere. 
B)  The hands of the clock move slower and slower until they and the clock itself stop at the event horizon. 
C)  As the clock nears the event horizon, the hands begin to move randomly as time becomes jumbled near the black hole. 
D)  The hands of the clock move faster and faster until the clock plunges through the event horizon.

Question 5

What is a singularity?

Accepted Answer

A)  particle-antiparticle pair 
B)  tunnel into another universe 
C)  point at the Schwarzschild radius of a black hole 
D)  point of infinite density 
A)  particle-antiparticle pair 
B)  tunnel into another universe 
C)  point at the Schwarzschild radius of a black hole 
D)  point of infinite density

Question 6

The interior of a neutron star is believed to consist of:

Accepted Answer

A)  neutrons compressed into a crystalline lattice structure by very high pressure. 
B)  a dense gas consisting mostly of neutrons. 
C)  a metallic fluid of almost pure iron. 
D)  neutrons in a superfluid state. 
A)  neutrons compressed into a crystalline lattice structure by very high pressure. 
B)  a dense gas consisting mostly of neutrons. 
C)  a metallic fluid of almost pure iron. 
D)  neutrons in a superfluid state.

Question 7

Which property does NOT characterize a supergiant star?

Accepted Answer

A)  high mass-loss rates caused by enormous stellar winds 
B)  longer and longer time periods required to complete each stage in nucleosynthesis because of the large amount of fuel to be consumed 
C)  circumstellar shells of ejected gas 
D)  fusion in concentric shells surrounding the core 
A)  high mass-loss rates caused by enormous stellar winds 
B)  longer and longer time periods required to complete each stage in nucleosynthesis because of the large amount of fuel to be consumed 
C)  circumstellar shells of ejected gas 
D)  fusion in concentric shells surrounding the core

Question 8

The very strong magnetic field on a neutron star is created by:

Accepted Answer

A)  the collapse of the star, which significantly intensifies the original weak magnetic field of the star. 
B)  differential rotation of the star, with the equator rotating faster than the poles, similar to sunspot formation. 
C)  a burst of neutrinos produced by the supernova explosion, the equivalent of a very large electrical current flowing for a short time. 
D)  turbulence in the electrical plasmas during the collapse of the star; the original star would have had no magnetic field. 
A)  the collapse of the star, which significantly intensifies the original weak magnetic field of the star. 
B)  differential rotation of the star, with the equator rotating faster than the poles, similar to sunspot formation. 
C)  a burst of neutrinos produced by the supernova explosion, the equivalent of a very large electrical current flowing for a short time. 
D)  turbulence in the electrical plasmas during the collapse of the star; the original star would have had no magnetic field.

Question 9

What is the Chandrasekhar limit?

Accepted Answer

A)  the time limit of the existence of a planetary nebula, beyond which the nebula dissipates and becomes too rarified to see 
B)  the time limit for the transfer of mass to a white dwarf in a close binary system, beyond which the white dwarf erupts in a nova 
C)  the mass limit to the total mass of a white dwarf, beyond which it will erupt in a nova 
D)  the mass limit to the total mass of a white dwarf, beyond which the electron degeneracy pressure will be overcome and the core will collapse 
A)  the time limit of the existence of a planetary nebula, beyond which the nebula dissipates and becomes too rarified to see 
B)  the time limit for the transfer of mass to a white dwarf in a close binary system, beyond which the white dwarf erupts in a nova 
C)  the mass limit to the total mass of a white dwarf, beyond which it will erupt in a nova 
D)  the mass limit to the total mass of a white dwarf, beyond which the electron degeneracy pressure will be overcome and the core will collapse

Question 10

In what way is the general theory of relativity more "general" (i.e.,deals with more situations)than the special theory of relativity?

Accepted Answer

A)  The general theory includes gravitation and accelerated motion. 
B)  The general theory includes the change in the rate of passage of time when objects are in motion. 
C)  The general theory includes motion at and above the speed of light. 
D)  The general theory includes only constant, unaccelerated motion. 
A)  The general theory includes gravitation and accelerated motion. 
B)  The general theory includes the change in the rate of passage of time when objects are in motion. 
C)  The general theory includes motion at and above the speed of light. 
D)  The general theory includes only constant, unaccelerated motion.

Question 11

Suppose you see a spaceship with a clock on it hurtling past you at 80% of the speed of light.As it goes by,the second hand on the ship's clock ticks off five seconds.How much time elapsed on your clock during this occurrence?

Accepted Answer

A)  more than 5 seconds if the spaceship is approaching you and less than 5 seconds if it is moving away from you 
B)  less than 5 seconds 
C)  more than 5 seconds 
D)  5 seconds-the same as on the ship's clock 
A)  more than 5 seconds if the spaceship is approaching you and less than 5 seconds if it is moving away from you 
B)  less than 5 seconds 
C)  more than 5 seconds 
D)  5 seconds-the same as on the ship's clock

Question 12

In the asymptotic giant branch (AGB)phase of their lives,stars like the Sun lose mass to space through an outflowing "stellar wind." Over a period of 1000 years,how much mass would such a star eject?

Accepted Answer

A)  almost 1/10 solar mass 
B)  about 10-⁵ solar mass 
C)  about 1/100 solar mass 
D)  almost none since most of the mass flows back in at the star's poles 
A)  almost 1/10 solar mass 
B)  about 10-⁵ solar mass 
C)  about 1/100 solar mass 
D)  almost none since most of the mass flows back in at the star's poles

Question 13

A clock is moving across your line of sight with its face turned toward you.Which statement about this clock,as seen by you,is NOT correct?

Accepted Answer

A)  The clock will run slow compared with a clock in your hand. 
B)  The clock will appear shorter than it would if it were at rest. 
C)  The clock will appear thinner, front to back, than it would if it were at rest. 
D)  The clock will appear denser than it would if it were at rest. 
A)  The clock will run slow compared with a clock in your hand. 
B)  The clock will appear shorter than it would if it were at rest. 
C)  The clock will appear thinner, front to back, than it would if it were at rest. 
D)  The clock will appear denser than it would if it were at rest.

Question 14

Pulsating X-ray sources with periods of a few seconds are caused by:

Accepted Answer

A)  the eclipsing of an X-ray-emitting star with a very hot surface by a cool companion in a close binary system. 
B)  the pulsation in radius, temperature, and hence luminosity of a hot Cepheid variable star with a surface temperature hot enough to emit X-rays. 
C)  matter falling violently onto the surface of a rotating neutron star from a close companion in a binary star system, causing an X-ray hot spot that disappears periodically behind the neutron star. 
D)  matter falling onto the surface of a very hot, rotating white dwarf from an ordinary companion star in a binary system, producing an X-ray-emitting hot spot that disappears periodically behind the white dwarf. 
A)  the eclipsing of an X-ray-emitting star with a very hot surface by a cool companion in a close binary system. 
B)  the pulsation in radius, temperature, and hence luminosity of a hot Cepheid variable star with a surface temperature hot enough to emit X-rays. 
C)  matter falling violently onto the surface of a rotating neutron star from a close companion in a binary star system, causing an X-ray hot spot that disappears periodically behind the neutron star. 
D)  matter falling onto the surface of a very hot, rotating white dwarf from an ordinary companion star in a binary system, producing an X-ray-emitting hot spot that disappears periodically behind the white dwarf.

Question 15

Most supernova remnants have been discovered by observing in which wavelength region?

Accepted Answer

A)  gamma ray 
B)  ultraviolet 
C)  visible 
D)  radio 
A)  gamma ray 
B)  ultraviolet 
C)  visible 
D)  radio

Question 16

How much energy does a typical longer-living gamma-ray burster emit in 100 seconds?

Accepted Answer

A)  as much as the Sun in 100 years 
B)  as much as the Sun in a month 
C)  as much as the Sun since the demise of the dinosaurs 
D)  as much as the Sun over its entire lifetime 
A)  as much as the Sun in 100 years 
B)  as much as the Sun in a month 
C)  as much as the Sun since the demise of the dinosaurs 
D)  as much as the Sun over its entire lifetime

Question 17

Take two identical,non-rotating,5-solar-mass black holes and place them side by side.Add 1 solar mass of pineapples to the left-hand one and 1 solar mass of uranium to the right-hand one (without changing the electrical charge or the rotation of either black hole).How will the two black holes differ?

Accepted Answer

A)  The right-hand black hole will have a stronger gravitational field because of the denser material inside it. 
B)  The two black holes will not differ at all. 
C)  The left-hand black hole will smell better. 
D)  The right-hand black hole will be radioactive, emitting alpha particles, electrons, and gamma rays into space. 
A)  The right-hand black hole will have a stronger gravitational field because of the denser material inside it. 
B)  The two black holes will not differ at all. 
C)  The left-hand black hole will smell better. 
D)  The right-hand black hole will be radioactive, emitting alpha particles, electrons, and gamma rays into space.

Question 18

What is believed to be the source of ultra-high-energy cosmic rays?

Accepted Answer

A)  active supernovae 
B)  globular clusters 
C)  black holes 
D)  quasars 
A)  active supernovae 
B)  globular clusters 
C)  black holes 
D)  quasars

Question 19

When a massive star collapses into a Type II supernova,elements heavier than iron are created.But the amounts of these elements that survive such the collapse are not sufficient to account for the amounts we see in the universe.Where are/were a great many of them probably produced?

Accepted Answer

A)  Type Ia supernovae 
B)  the original Big Bang at the origin of the universe 
C)  collisions of neutron stars 
D)  nucleosynthesis in the cores of smaller but more numerous stars, like the Sun 
A)  Type Ia supernovae 
B)  the original Big Bang at the origin of the universe 
C)  collisions of neutron stars 
D)  nucleosynthesis in the cores of smaller but more numerous stars, like the Sun

Question 20

Einstein's theory of special relativity contains some very strange ideas such as time dilation (moving clocks run slow),length contraction (moving lengths are shorter),and lack of absolute simultaneity.What is the basis of these ideas?

Accepted Answer

A)  New technologies allow more precise measurements of length and time than had been possible in Newton's era, and the theory had to be reworked to fit this new evidence. 
B)  The speed of light is the same for all observers in all reference frames. 
C)  The ether (the medium that supports the passage of light) proved to be denser than originally thought. 
D)  The fabric of spacetime is dominated by black holes. 
A)  New technologies allow more precise measurements of length and time than had been possible in Newton's era, and the theory had to be reworked to fit this new evidence. 
B)  The speed of light is the same for all observers in all reference frames. 
C)  The ether (the medium that supports the passage of light) proved to be denser than originally thought. 
D)  The fabric of spacetime is dominated by black holes.

Are crystalline stars or crystalline remnants of stars possible? Why or why not?

At which location will Newton's laws of motion be inadequate in describing precisely the motions of objects?

Supernovae are detected:

A laborer repairing the clock tower on a space station orbiting a black hole accidentally drops the clock in such a way that it accelerates toward the black hole.What does the worker see while watching the clock?

What is a singularity?

The interior of a neutron star is believed to consist of:

Which property does NOT characterize a supergiant star?

The very strong magnetic field on a neutron star is created by:

What is the Chandrasekhar limit?

In what way is the general theory of relativity more "general" (i.e.,deals with more situations)than the special theory of relativity?

Suppose you see a spaceship with a clock on it hurtling past you at 80% of the speed of light.As it goes by,the second hand on the ship's clock ticks off five seconds.How much time elapsed on your clock during this occurrence?

In the asymptotic giant branch (AGB)phase of their lives,stars like the Sun lose mass to space through an outflowing "stellar wind." Over a period of 1000 years,how much mass would such a star eject?

A clock is moving across your line of sight with its face turned toward you.Which statement about this clock,as seen by you,is NOT correct?

Pulsating X-ray sources with periods of a few seconds are caused by:

Most supernova remnants have been discovered by observing in which wavelength region?

How much energy does a typical longer-living gamma-ray burster emit in 100 seconds?

What is believed to be the source of ultra-high-energy cosmic rays?

When a massive star collapses into a Type II supernova,elements heavier than iron are created.But the amounts of these elements that survive such the collapse are not sufficient to account for the amounts we see in the universe.Where are/were a great many of them probably produced?

Einstein's theory of special relativity contains some very strange ideas such as time dilation (moving clocks run slow),length contraction (moving lengths are shorter),and lack of absolute simultaneity.What is the basis of these ideas?

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

Are crystalline stars or crystalline remnants of stars possible? Why or why not?

At which location will Newton's laws of motion be inadequate in describing precisely the motions of objects?

Supernovae are detected:

A laborer repairing the clock tower on a space station orbiting a black hole accidentally drops the clock in such a way that it accelerates toward the black hole.What does the worker see while watching the clock?

What is a singularity?

The interior of a neutron star is believed to consist of:

Which property does NOT characterize a supergiant star?

The very strong magnetic field on a neutron star is created by:

What is the Chandrasekhar limit?

In what way is the general theory of relativity more "general" (i.e.,deals with more situations)than the special theory of relativity?

Suppose you see a spaceship with a clock on it hurtling past you at 80% of the speed of light.As it goes by,the second hand on the ship's clock ticks off five seconds.How much time elapsed on your clock during this occurrence?

In the asymptotic giant branch (AGB)phase of their lives,stars like the Sun lose mass to space through an outflowing "stellar wind." Over a period of 1000 years,how much mass would such a star eject?

A clock is moving across your line of sight with its face turned toward you.Which statement about this clock,as seen by you,is NOT correct?

Pulsating X-ray sources with periods of a few seconds are caused by:

Most supernova remnants have been discovered by observing in which wavelength region?

How much energy does a typical longer-living gamma-ray burster emit in 100 seconds?

What is believed to be the source of ultra-high-energy cosmic rays?

When a massive star collapses into a Type II supernova,elements heavier than iron are created.But the amounts of these elements that survive such the collapse are not sufficient to account for the amounts we see in the universe.Where are/were a great many of them probably produced?

Einstein's theory of special relativity contains some very strange ideas such as time dilation (moving clocks run slow),length contraction (moving lengths are shorter),and lack of absolute simultaneity.What is the basis of these ideas?

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