Question 1

When electrons are squeezed closer together,they obtain a wide range of velocities.What physical principle does this reflect?

Accepted Answer

The Heisen

Question 2

Which of the following phases lasts for the shortest time as a massive star evolves?

Accepted Answer

A)  hydrogen burning 
B)  helium burning 
C)  oxygen burning 
D)  silicon burning 
A)  hydrogen burning 
B)  helium burning 
C)  oxygen burning 
D)  silicon burning

Question 3

How can a binary companion affect a star's evolution?

Accepted Answer

Nearby binary compan

Question 4

What produces the two shock waves in the classic picture of spherical planetary nebulae,as shown in the figure below?

Accepted Answer

The shocks are produced by the

Question 5

In order from least to most massive,what are the possible remnants of stars that run out of fuel for fusion?

Accepted Answer

White dwar

Question 6

The period between pulses from a particular pulsar increases slowly with time.This implies that the:

Accepted Answer

A)  pulsar's magnetic axis is shifting with time. 
B)  pulsar is moving away from the observer. 
C)  pulsar has a binary companion. 
D)  pulsar's radiation carries angular momentum. 
A)  pulsar's magnetic axis is shifting with time. 
B)  pulsar is moving away from the observer. 
C)  pulsar has a binary companion. 
D)  pulsar's radiation carries angular momentum.

Question 7

Why are pulsars periodic?

Accepted Answer

A)  Their magnetic fields oscillate. 
B)  They have hot spots on their surfaces. 
C)  They are periodically blocked by binary companions. 
D)  Their radiation sweeps across Earth periodically. 
A)  Their magnetic fields oscillate. 
B)  They have hot spots on their surfaces. 
C)  They are periodically blocked by binary companions. 
D)  Their radiation sweeps across Earth periodically.

Question 8

What happens when a massive star's core becomes iron?

Accepted Answer

A)  The star begins to fuse iron into nickel. 
B)  The star begins to pulsate as a variable star. 
C)  The star becomes a planetary nebula. 
D)  The star can no longer support itself against gravity. 
A)  The star begins to fuse iron into nickel. 
B)  The star begins to pulsate as a variable star. 
C)  The star becomes a planetary nebula. 
D)  The star can no longer support itself against gravity.

Question 9

The figure below shows three white dwarfs on an HR diagram.Which of these three is oldest?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  The answer cannot be determined from this HR diagram. 
A)  A 
B)  B 
C)  C 
D)  The answer cannot be determined from this HR diagram.

Question 10

Suppose that the binding energy per nucleon of oxygen was larger than the binding energy per nucleon of silicon.How would this change stellar evolution?

Accepted Answer

Stars could not gain energy by

Question 11

Which of the following describes the evolutionary stages of a star with three times the mass of the Sun?

Accepted Answer

A)  horizontal branch, main sequence, red giant, asymptotic giant branch 
B)  main sequence, asymptotic giant branch, red giant, horizontal branch 
C)  main sequence, horizontal branch, red giant, asymptotic giant branch 
D)  main sequence, red giant, horizontal branch, asymptotic giant branch 
A)  horizontal branch, main sequence, red giant, asymptotic giant branch 
B)  main sequence, asymptotic giant branch, red giant, horizontal branch 
C)  main sequence, horizontal branch, red giant, asymptotic giant branch 
D)  main sequence, red giant, horizontal branch, asymptotic giant branch

Question 12

If the initial mass function changed to form more high-mass stars,how would the overall elemental composition of the Universe be different?

Accepted Answer

There would be more

Question 13

Why is an intermediate mass star's time on the horizontal branch much shorter than its time on the main sequence?

Accepted Answer

The star is more luminous (so

Question 14

Why does stellar fusion end with an iron core?

Accepted Answer

A)  The core becomes so hot it expands too much. 
B)  Iron cannot undergo fusion. 
C)  Iron does not produce energy when it undergoes fusion. 
D)  Iron requires such a high temperature for fusion that it does not occur inside stars. 
A)  The core becomes so hot it expands too much. 
B)  Iron cannot undergo fusion. 
C)  Iron does not produce energy when it undergoes fusion. 
D)  Iron requires such a high temperature for fusion that it does not occur inside stars.

Question 15

According to recent models,supernova explosions are driven by:

Accepted Answer

A)  shock waves from rebounding gas. 
B)  absorption of light from the collapsing core. 
C)  neutrino flows. 
D)  magnetic fields. 
A)  shock waves from rebounding gas. 
B)  absorption of light from the collapsing core. 
C)  neutrino flows. 
D)  magnetic fields.

Question 16

Which of the following determines the rate at which a star generates energy in its core?

Accepted Answer

A)  the star's composition 
B)  electromagnetism 
C)  the efficiency of fusion reactions 
D)  mass 
A)  the star's composition 
B)  electromagnetism 
C)  the efficiency of fusion reactions 
D)  mass

Question 17

The figure below shows the evolutionary path of a star on the HR diagram.At which point does helium fusion begin?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
A)  A 
B)  B 
C)  C 
D)  D

Question 18

What supports a white dwarf star against gravity?

Accepted Answer

A)  thermal pressure 
B)  fusion 
C)  electron degeneracy pressure 
D)  the strong nuclear force 
A)  thermal pressure 
B)  fusion 
C)  electron degeneracy pressure 
D)  the strong nuclear force

Question 19

Two stars orbit each other as a close binary system.When the system forms,star A has 10 solar masses and star B has 3 solar masses.Which of the following is most likely to happen in the future?

Accepted Answer

A)  Star A will transfer mass to star B. 
B)  Star B will transfer mass to star A. 
C)  The stars will merge. 
D)  Radiation from star B will disrupt star A. 
A)  Star A will transfer mass to star B. 
B)  Star B will transfer mass to star A. 
C)  The stars will merge. 
D)  Radiation from star B will disrupt star A.

Question 20

An astronomer detects a Type Ia supernova in a distant galaxy.In order to measure the distance to the galaxy using the supernova,what must the astronomer measure?

Accepted Answer

The brightness of th

When electrons are squeezed closer together,they obtain a wide range of velocities.What physical principle does this reflect?

Which of the following phases lasts for the shortest time as a massive star evolves?

How can a binary companion affect a star's evolution?

What produces the two shock waves in the classic picture of spherical planetary nebulae,as shown in the figure below?

In order from least to most massive,what are the possible remnants of stars that run out of fuel for fusion?

The period between pulses from a particular pulsar increases slowly with time.This implies that the:

Why are pulsars periodic?

What happens when a massive star's core becomes iron?

The figure below shows three white dwarfs on an HR diagram.Which of these three is oldest?

Suppose that the binding energy per nucleon of oxygen was larger than the binding energy per nucleon of silicon.How would this change stellar evolution?

Which of the following describes the evolutionary stages of a star with three times the mass of the Sun?

If the initial mass function changed to form more high-mass stars,how would the overall elemental composition of the Universe be different?

Why is an intermediate mass star's time on the horizontal branch much shorter than its time on the main sequence?

Why does stellar fusion end with an iron core?

According to recent models,supernova explosions are driven by:

Which of the following determines the rate at which a star generates energy in its core?

The figure below shows the evolutionary path of a star on the HR diagram.At which point does helium fusion begin?

What supports a white dwarf star against gravity?

Two stars orbit each other as a close binary system.When the system forms,star A has 10 solar masses and star B has 3 solar masses.Which of the following is most likely to happen in the future?

An astronomer detects a Type Ia supernova in a distant galaxy.In order to measure the distance to the galaxy using the supernova,what must the astronomer measure?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

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Exam 13: To the Graveyard of Stars: the End Points of Stellar Evolution

When electrons are squeezed closer together,they obtain a wide range of velocities.What physical principle does this reflect?

Which of the following phases lasts for the shortest time as a massive star evolves?

How can a binary companion affect a star's evolution?

What produces the two shock waves in the classic picture of spherical planetary nebulae,as shown in the figure below?

In order from least to most massive,what are the possible remnants of stars that run out of fuel for fusion?

The period between pulses from a particular pulsar increases slowly with time.This implies that the:

Why are pulsars periodic?

What happens when a massive star's core becomes iron?

The figure below shows three white dwarfs on an HR diagram.Which of these three is oldest?

Suppose that the binding energy per nucleon of oxygen was larger than the binding energy per nucleon of silicon.How would this change stellar evolution?

Which of the following describes the evolutionary stages of a star with three times the mass of the Sun?

If the initial mass function changed to form more high-mass stars,how would the overall elemental composition of the Universe be different?

Why is an intermediate mass star's time on the horizontal branch much shorter than its time on the main sequence?

Why does stellar fusion end with an iron core?

According to recent models,supernova explosions are driven by:

Which of the following determines the rate at which a star generates energy in its core?

The figure below shows the evolutionary path of a star on the HR diagram.At which point does helium fusion begin?

What supports a white dwarf star against gravity?

Two stars orbit each other as a close binary system.When the system forms,star A has 10 solar masses and star B has 3 solar masses.Which of the following is most likely to happen in the future?

An astronomer detects a Type Ia supernova in a distant galaxy.In order to measure the distance to the galaxy using the supernova,what must the astronomer measure?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters