Question 1

One star in a binary will almost always become a red giant before the other because:

Accepted Answer

A)  one star is always larger than the other. 
B)  binaries always have one star twice as massive as the other. 
C)  small differences in main-sequence masses yield large differences in main-sequence lifetimes. 
D)  the more massive binary star always gets more mass from the less massive binary star when both are main-sequence stars. 
A)  one star is always larger than the other. 
B)  binaries always have one star twice as massive as the other. 
C)  small differences in main-sequence masses yield large differences in main-sequence lifetimes. 
D)  the more massive binary star always gets more mass from the less massive binary star when both are main-sequence stars. C

Question 2

What would you need to measure for a planetary nebula (see the image below)to determine how long ago its parent star died?

Accepted Answer

A)  the mass of the white dwarf 
B)  the mass and radius of the white dwarf 
C)  the nebula's temperature and radius 
D)  the nebula's radius and expansion velocity 
A)  the mass of the white dwarf 
B)  the mass and radius of the white dwarf 
C)  the nebula's temperature and radius 
D)  the nebula's radius and expansion velocity D

Question 3

As a solar-type star evolves off the main sequence,its:

Accepted Answer

A)  core and envelope expand. 
B)  core and envelope shrink. 
C)  core shrinks and envelope expands. 
D)  core expands and envelope shrinks. 
A)  core and envelope expand. 
B)  core and envelope shrink. 
C)  core shrinks and envelope expands. 
D)  core expands and envelope shrinks. C

Question 4

When helium fusion begins in the core of a red giant star,the situation quickly gets out of control because electron-degeneracy pressure does not respond to changes in:

Accepted Answer

A)  luminosity. 
B)  density. 
C)  gravity. 
D)  temperature. 
A)  luminosity. 
B)  density. 
C)  gravity. 
D)  temperature.

Question 5

What types of chemical elements can low-mass stars contribute to the enrichment of the interstellar medium,and how are they produced?

Accepted Answer

Low-mass stars can enrich the interstell

Question 6

A 1-M¤ star in a binary system could create the following chemical element and eject it into the interstellar medium:

Accepted Answer

A)  carbon. 
B)  helium. 
C)  iron. 
D)  all of the above 
A)  carbon. 
B)  helium. 
C)  iron. 
D)  all of the above

Question 7

The figure below shows the H-R diagram of stars from the cluster 47 Tucanae.Explain what the main-sequence turnoff is and how it can be used to determine the age of the cluster.

Accepted Answer

The main-sequence turnoff of a cluster i

Question 8

During which phase of the evolution of a low-mass star does it have two separate regions of nuclear burning occurring in its interior?

Accepted Answer

A)  main sequence 
B)  red giant 
C)  horizontal branch 
D)  white dwarf 
A)  main sequence 
B)  red giant 
C)  horizontal branch 
D)  white dwarf

Question 9

Helium burns in the core of a horizontal branch star via ________ and produces ________.

Accepted Answer

A)  the triple-alpha reaction; carbon 
B)  the proton-proton chain; lithium 
C)  the triple-alpha reaction; oxygen 
D)  the proton-proton chain; iron 
A)  the triple-alpha reaction; carbon 
B)  the proton-proton chain; lithium 
C)  the triple-alpha reaction; oxygen 
D)  the proton-proton chain; iron

Question 10

What occurs if a white dwarf exceeds the Chandrasekhar limit?

Accepted Answer

A)  Nothing, the white dwarf just gets bigger. 
B)  The white dwarf contracts to a smaller, hotter object. 
C)  a nova explosion 
D)  a type Ia supernova explosion 
A)  Nothing, the white dwarf just gets bigger. 
B)  The white dwarf contracts to a smaller, hotter object. 
C)  a nova explosion 
D)  a type Ia supernova explosion

Question 11

What particles are degenerate in a white dwarf?

Accepted Answer

Only the electrons a

Question 12

How can the core of a star be degenerate with respect to the electrons but nondegenerate with respect to the nuclei?

Accepted Answer

(1)Quantum mechanics says electrons take

Question 13

Suppose you measured H-R diagrams for the two star clusters pictured below.  
Which of the following statements is TRUE?

Accepted Answer

A)  Cluster A is younger than Cluster B. 
B)  Cluster A is closer to us than Cluster B. 
C)  Both a and b are TRUE. 
D)  Both a and b are FALSE. 
A)  Cluster A is younger than Cluster B. 
B)  Cluster A is closer to us than Cluster B. 
C)  Both a and b are TRUE. 
D)  Both a and b are FALSE.

Question 14

As a red giant star evolves,hydrogen shell burning proceeds increasingly faster due to:

Accepted Answer

A)  rotational energy from the star's rapid rotation. 
B)  heat released from the core's contraction. 
C)  pressure from the contracting envelope. 
D)  this is a trick question; hydrogen actually burns increasingly slower with time. 
A)  rotational energy from the star's rapid rotation. 
B)  heat released from the core's contraction. 
C)  pressure from the contracting envelope. 
D)  this is a trick question; hydrogen actually burns increasingly slower with time.

Question 15

The Sun will likely stop being a main-sequence star in:

Accepted Answer

A)  5,000 years. 
B)  5 million years. 
C)  500 million years. 
D)  5 billion years. 
A)  5,000 years. 
B)  5 million years. 
C)  500 million years. 
D)  5 billion years.

Question 16

In stellar fusion,the term "ash" refers to:

Accepted Answer

A)  a dusty product of fire from oxidation occurring within the core of the star. 
B)  the result of nuclear fusion that collects in the core. 
C)  the result of nuclear fusion that collects in the outer layers of a star. 
D)  a dusty product of fire from oxidation occurring in the outer layers of the star. 
A)  a dusty product of fire from oxidation occurring within the core of the star. 
B)  the result of nuclear fusion that collects in the core. 
C)  the result of nuclear fusion that collects in the outer layers of a star. 
D)  a dusty product of fire from oxidation occurring in the outer layers of the star.

Question 17

Suppose you observe three star clusters.Cluster 1 has a main-sequence turnoff point at spectral type G,cluster 2 has a turnoff point at spectral type A,and cluster 3 has a turnoff point at spectral type B.Which cluster is youngest and which is oldest? Explain why.What is the approximate age of the oldest cluster?

Accepted Answer

Of the three types of main-sequence turn

Question 18

In a white dwarf,what is the source of pressure that halts its contraction as it cools?

Accepted Answer

A)  thermal pressure of the extremely hot gas 
B)  electrons packed so closely that they become incompressible 
C)  neutrons that resist being pressed further together 
D)  carbon nuclei that repulse each other strongly because they each contain six protons 
A)  thermal pressure of the extremely hot gas 
B)  electrons packed so closely that they become incompressible 
C)  neutrons that resist being pressed further together 
D)  carbon nuclei that repulse each other strongly because they each contain six protons

Question 19

Using the figure below,describe how the composition of the Sun varies by radius over time.

Accepted Answer

The core of the Sun will conta

Question 20

A star's surface temperature during the horizontal branch phase is determined primarily by its:

Accepted Answer

A)  luminosity. 
B)  chemical composition. 
C)  magnetic field strength. 
D)  rotation rate. 
A)  luminosity. 
B)  chemical composition. 
C)  magnetic field strength. 
D)  rotation rate.

One star in a binary will almost always become a red giant before the other because:

What would you need to measure for a planetary nebula (see the image below)to determine how long ago its parent star died?

As a solar-type star evolves off the main sequence,its:

When helium fusion begins in the core of a red giant star,the situation quickly gets out of control because electron-degeneracy pressure does not respond to changes in:

What types of chemical elements can low-mass stars contribute to the enrichment of the interstellar medium,and how are they produced?

A 1-M¤ star in a binary system could create the following chemical element and eject it into the interstellar medium:

The figure below shows the H-R diagram of stars from the cluster 47 Tucanae.Explain what the main-sequence turnoff is and how it can be used to determine the age of the cluster.

During which phase of the evolution of a low-mass star does it have two separate regions of nuclear burning occurring in its interior?

Helium burns in the core of a horizontal branch star via and produces .

What occurs if a white dwarf exceeds the Chandrasekhar limit?

What particles are degenerate in a white dwarf?

How can the core of a star be degenerate with respect to the electrons but nondegenerate with respect to the nuclei?

Suppose you measured H-R diagrams for the two star clusters pictured below. Which of the following statements is TRUE?

As a red giant star evolves,hydrogen shell burning proceeds increasingly faster due to:

The Sun will likely stop being a main-sequence star in:

In stellar fusion,the term "ash" refers to:

In a white dwarf,what is the source of pressure that halts its contraction as it cools?

Using the figure below,describe how the composition of the Sun varies by radius over time.

A star's surface temperature during the horizontal branch phase is determined primarily by its:

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: the Sun

Evolution of High-Mass Stars

Measuring Galaxies

Our Galaxy: the Milky Way

The Evolution of the Universe

Formation of Structure

Life in the Universe

Filters

Exam 12: Evolution of Low-Mass Stars

One star in a binary will almost always become a red giant before the other because:

What would you need to measure for a planetary nebula (see the image below)to determine how long ago its parent star died?

As a solar-type star evolves off the main sequence,its:

When helium fusion begins in the core of a red giant star,the situation quickly gets out of control because electron-degeneracy pressure does not respond to changes in:

What types of chemical elements can low-mass stars contribute to the enrichment of the interstellar medium,and how are they produced?

A 1-M¤ star in a binary system could create the following chemical element and eject it into the interstellar medium:

The figure below shows the H-R diagram of stars from the cluster 47 Tucanae.Explain what the main-sequence turnoff is and how it can be used to determine the age of the cluster.

During which phase of the evolution of a low-mass star does it have two separate regions of nuclear burning occurring in its interior?

Helium burns in the core of a horizontal branch star via ________ and produces ________.

What occurs if a white dwarf exceeds the Chandrasekhar limit?

What particles are degenerate in a white dwarf?

How can the core of a star be degenerate with respect to the electrons but nondegenerate with respect to the nuclei?

Suppose you measured H-R diagrams for the two star clusters pictured below. Which of the following statements is TRUE?

As a red giant star evolves,hydrogen shell burning proceeds increasingly faster due to:

The Sun will likely stop being a main-sequence star in:

In stellar fusion,the term "ash" refers to:

In a white dwarf,what is the source of pressure that halts its contraction as it cools?

Using the figure below,describe how the composition of the Sun varies by radius over time.

A star's surface temperature during the horizontal branch phase is determined primarily by its:

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: the Sun

Evolution of High-Mass Stars

Measuring Galaxies

Our Galaxy: the Milky Way

The Evolution of the Universe

Formation of Structure

Life in the Universe

Filters

Helium burns in the core of a horizontal branch star via and produces .