Question 1

What is the term for the distance from a black hole at which the escape velocity is approximately equal to the speed of light?

Accepted Answer

A) Lagrangian point 
B) Chandrasekhar-Landau limit 
C) Hubble radius 
D) Schwarzschild radius 
A) Lagrangian point 
B) Chandrasekhar-Landau limit 
C) Hubble radius 
D) Schwarzschild radius

Question 2

What is the density of a neutron star?

Accepted Answer

A) about the same as that of a white dwarf 
B) about the same as that of the Sun 
C) about the same as that of an atomic nucleus 
D) zero 
A) about the same as that of a white dwarf 
B) about the same as that of the Sun 
C) about the same as that of an atomic nucleus 
D) zero

Question 3

Do all supernova remnants contain pulsars?

Accepted Answer

A) Yes, pulsars are visible in all supernova remnants. 
B) No, some supernova explosions form white dwarfs instead of the neutron stars necessary for pulsars. 
C) No: all supernova remnants start out having pulsars but the pulsars can disappear before the supernova remnant dissipates. 
D) Yes, but some pulsars' pulses are not visible from Earth because of the direction of their rotational axis. 
A) Yes, pulsars are visible in all supernova remnants. 
B) No, some supernova explosions form white dwarfs instead of the neutron stars necessary for pulsars. 
C) No: all supernova remnants start out having pulsars but the pulsars can disappear before the supernova remnant dissipates. 
D) Yes, but some pulsars' pulses are not visible from Earth because of the direction of their rotational axis.

Question 4

What is odd about the existence of planets around PSR J1257+12?

Accepted Answer

A) The gravitational pull of the pulsar should have pulled the planets down onto it. 
B) Planets would not be expected to survive the supernova explosion that created the pulsar. 
C) The planets should have been destroyed by the radiation from the pulsar. 
D) The pulsar is rotating so fast that the planets should have been flung into space. 
A) The gravitational pull of the pulsar should have pulled the planets down onto it. 
B) Planets would not be expected to survive the supernova explosion that created the pulsar. 
C) The planets should have been destroyed by the radiation from the pulsar. 
D) The pulsar is rotating so fast that the planets should have been flung into space.

Question 5

About how long will a 0.5 solar mass star spend on the main sequence?

Accepted Answer

A) 5 million years 
B) 570 million years 
C) 5 billion years 
D) 57 billion years 
A) 5 million years 
B) 570 million years 
C) 5 billion years 
D) 57 billion years

Question 6

The age of a star cluster can be determined from the ____________________ of the cluster.

Accepted Answer

The answer of The age of a star cluster can...

Question 7

Stars that are less massive than 0.4 solar mass never become giant stars.

Accepted Answer

A) True 
 B)False

Question 8

Why is the name pulsar a poor description of the object?

Accepted Answer

A) Pulsars are neutron stars. 
B) Pulsars' radio emissions are irregular. 
C) Pulsars vibrate rather than pulsate. 
D) Pulsars flash rather than pulsate. 
A) Pulsars are neutron stars. 
B) Pulsars' radio emissions are irregular. 
C) Pulsars vibrate rather than pulsate. 
D) Pulsars flash rather than pulsate.

Question 9

-On the diagram,draw the evolutionary track of the Sun from the time it reaches the main sequence until it becomes a white dwarf.Label the major stages on this track.

Accepted Answer

To draw the evolutionary track of the Su

Question 10

-Refer to the H-R diagram.How would the H-R diagram of a more distant star cluster look different?

Accepted Answer

A) The points would shift down, because all of the stars would have larger apparent magnitudes. 
B) The points would shift to the right, because all of the stars would appear to be cooler. 
C) The points would shift up, because all of the stars would have smaller apparent magnitudes. 
D) The points would shift to the left, because all of the stars would appear to be hotter. 
A) The points would shift down, because all of the stars would have larger apparent magnitudes. 
B) The points would shift to the right, because all of the stars would appear to be cooler. 
C) The points would shift up, because all of the stars would have smaller apparent magnitudes. 
D) The points would shift to the left, because all of the stars would appear to be hotter.

Question 11

What type of object is the Crab nebula?

Accepted Answer

A) a planetary nebula 
B) an open cluster 
C) an absorption nebula 
D) a supernova remnant 
A) a planetary nebula 
B) an open cluster 
C) an absorption nebula 
D) a supernova remnant

Question 12

How are neutron stars and white dwarfs similar?

Accepted Answer

The answer of How are neutron stars and white dwarfs...

Question 13

If main-sequence stars are supported by gas pressure,what supports a white dwarf?

Accepted Answer

A white dwarf is supported against gravi

Question 14

Which of the following correctly describes a relationship between pressure,temperature,and density in degenerate matter?

Accepted Answer

A) Pressure depends only on the temperature. 
B) Pressure does not depend on temperature. 
C) Temperature depends only on density. 
D) Pressure does not depend on density. 
A) Pressure depends only on the temperature. 
B) Pressure does not depend on temperature. 
C) Temperature depends only on density. 
D) Pressure does not depend on density.

Question 15

What is a planetary nebula?

Accepted Answer

A) the expelled outer envelope of a medium mass star 
B) a cloud of hot gas produced by a supernova explosion 
C) a nebula within which planets are forming 
D) a cloud of hot gas surrounding a planet 
A) the expelled outer envelope of a medium mass star 
B) a cloud of hot gas produced by a supernova explosion 
C) a nebula within which planets are forming 
D) a cloud of hot gas surrounding a planet

Question 16

When material expanding away from a star in a binary system reaches the edge of its Roche lobe,what happens?

Accepted Answer

A) The material will start to fall back toward the star. 
B) All of the material will accrete on to the companion. 
C) The material will no longer be gravitationally bound to the star. 
D) The material will increase in temperature and eventually undergo thermonuclear fusion. 
A) The material will start to fall back toward the star. 
B) All of the material will accrete on to the companion. 
C) The material will no longer be gravitationally bound to the star. 
D) The material will increase in temperature and eventually undergo thermonuclear fusion.

Question 17

Why are neutron stars expected to spin rapidly?

Accepted Answer

A) They conserve angular momentum when they collapse. 
B) They have high orbital velocities. 
C) They have high densities. 
D) The energy from the supernova explosion that formed them makes them spin faster. 
A) They conserve angular momentum when they collapse. 
B) They have high orbital velocities. 
C) They have high densities. 
D) The energy from the supernova explosion that formed them makes them spin faster.

Question 18

What is the difference between a supernova and a nova?

Accepted Answer

The answer of What is the difference between a supernova...

Question 19

Many pulsars have periods that are gradually getting longer as the spinning neutron stars lose energy.

Accepted Answer

A) True 
 B)False

Question 20

The rotation speed of pulsars slows down over time.What is believed to be the reason for this?

Accepted Answer

A) They are losing angular momentum into space via outward streaming particles. 
B) They are dragging companion stars around in their magnetic fields. 
C) They are conserving angular momentum. 
D) Their mass is increasing. 
A) They are losing angular momentum into space via outward streaming particles. 
B) They are dragging companion stars around in their magnetic fields. 
C) They are conserving angular momentum. 
D) Their mass is increasing.

What is the term for the distance from a black hole at which the escape velocity is approximately equal to the speed of light?

What is the density of a neutron star?

Do all supernova remnants contain pulsars?

What is odd about the existence of planets around PSR J1257+12?

About how long will a 0.5 solar mass star spend on the main sequence?

The age of a star cluster can be determined from the ____________________ of the cluster.

Stars that are less massive than 0.4 solar mass never become giant stars.

Why is the name pulsar a poor description of the object?

-On the diagram,draw the evolutionary track of the Sun from the time it reaches the main sequence until it becomes a white dwarf.Label the major stages on this track.

-Refer to the H-R diagram.How would the H-R diagram of a more distant star cluster look different?

What type of object is the Crab nebula?

How are neutron stars and white dwarfs similar?

If main-sequence stars are supported by gas pressure,what supports a white dwarf?

Which of the following correctly describes a relationship between pressure,temperature,and density in degenerate matter?

What is a planetary nebula?

When material expanding away from a star in a binary system reaches the edge of its Roche lobe,what happens?

Why are neutron stars expected to spin rapidly?

What is the difference between a supernova and a nova?

Many pulsars have periods that are gradually getting longer as the spinning neutron stars lose energy.

The rotation speed of pulsars slows down over time.What is believed to be the reason for this?

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Structure and Formation of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

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Exam 8: The Deaths of Stars

What is the term for the distance from a black hole at which the escape velocity is approximately equal to the speed of light?

What is the density of a neutron star?

Do all supernova remnants contain pulsars?

What is odd about the existence of planets around PSR J1257+12?

About how long will a 0.5 solar mass star spend on the main sequence?

The age of a star cluster can be determined from the ____________________ of the cluster.

Stars that are less massive than 0.4 solar mass never become giant stars.

Why is the name pulsar a poor description of the object?

-On the diagram,draw the evolutionary track of the Sun from the time it reaches the main sequence until it becomes a white dwarf.Label the major stages on this track.

-Refer to the H-R diagram.How would the H-R diagram of a more distant star cluster look different?

What type of object is the Crab nebula?

How are neutron stars and white dwarfs similar?

If main-sequence stars are supported by gas pressure,what supports a white dwarf?

Which of the following correctly describes a relationship between pressure,temperature,and density in degenerate matter?

What is a planetary nebula?

When material expanding away from a star in a binary system reaches the edge of its Roche lobe,what happens?

Why are neutron stars expected to spin rapidly?

What is the difference between a supernova and a nova?

Many pulsars have periods that are gradually getting longer as the spinning neutron stars lose energy.

The rotation speed of pulsars slows down over time.What is believed to be the reason for this?

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Structure and Formation of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

Filters