Question 1

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 B

Question 2

What is a planetary nebula?

Accepted Answer

A)  A planet surrounded by a glowing shell of gas 
B)  The disk of gas and dust surrounding a young star that will soon form a star system 
C)  The ejected envelope of a giant star surrounding the remains of a star 
D)  A type of young,medium-mass star 
A)  A planet surrounded by a glowing shell of gas 
B)  The disk of gas and dust surrounding a young star that will soon form a star system 
C)  The ejected envelope of a giant star surrounding the remains of a star 
D)  A type of young,medium-mass star C

Question 3

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 ages 
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 ages 
D)  the more massive binary star always gets more mass from the less massive binary star when both are main-sequence stars C

Question 4

A low-mass main-sequence star's climb up the red giant branch is halted by:

Accepted Answer

A)  the end of hydrogen shell burning 
B)  the beginning of helium fusion in the core 
C)  electron-degeneracy pressure in the core 
D)  instabilities in the star's expanding outer layers 
A)  the end of hydrogen shell burning 
B)  the beginning of helium fusion in the core 
C)  electron-degeneracy pressure in the core 
D)  instabilities in the star's expanding outer layers

Question 5

You observed three different star clusters and found that the main-sequence turnoff stars in Cluster 1 had spectral type A,the main-sequence turnoff stars in Cluster 2 had spectral type B,and the main-sequence turnoff stars in Cluster 3 had spectral type G.Which star cluster is the youngest?

Accepted Answer

A)  Cluster 1 
B)  Cluster 2 
C)  Cluster 3 
D)  It is impossible to determine their ages given only the spectral types. 
A)  Cluster 1 
B)  Cluster 2 
C)  Cluster 3 
D)  It is impossible to determine their ages given only the spectral types.

Question 6

A 1 M$\bigodot$ 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

Binary stars can evolve to become novae and supernovae because slight differences in mass can mean large differences in main-sequence lifetimes.

Accepted Answer

A) True 
 B)False

Question 8

Stars evolve primarily because they run out of fuel in their cores.

Accepted Answer

A) True 
 B)False

Question 9

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 10

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 11

In stellar fusion the term "ash" refers to:

Accepted Answer

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)  dusty product of fire from oxidation occurring in the outer layers of the star 
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)  dusty product of fire from oxidation occurring in the outer layers of the star

Question 12

About how long will a 2 M$\bigodot$star live as a main-sequence star?

Accepted Answer

A)  10 million years 
B)  1 billion years 
C)  10 billion years 
D)  100 million years 
A)  10 million years 
B)  1 billion years 
C)  10 billion years 
D)  100 million years

Question 13

When a star depletes its core supply of hydrogen,__________ dominates in the core and __________ dominates in the atmosphere.

Accepted Answer

A)  pressure; pressure 
B)  pressure; gravity 
C)  gravity; gravity 
D)  gravity; pressure 
A)  pressure; pressure 
B)  pressure; gravity 
C)  gravity; gravity 
D)  gravity; pressure

Question 14

The Ring Nebula (image below)is a planetary nebula that currently has a radius of 0.4 pc and an expansion velocity of 250 km/s.Approximately how long ago did its parent star die and eject its outer layers?

Accepted Answer

A)  1,600 years ago 
B)  3,200 years ago 
C)  5,400 years ago 
D)  28,000 years ago 
A)  1,600 years ago 
B)  3,200 years ago 
C)  5,400 years ago 
D)  28,000 years ago

Question 15

We can determine the age of a star cluster by measuring the color of the reddest red giant stars in the cluster.

Accepted Answer

A) True 
 B)False

Question 16

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 17

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 18

When the Sun becomes an AGB star,its radius will be approximately 100 R$\bigodot$.If its mass at this point will be approximately the same as it is now,how will its surface gravity as an AGB star compare to its present surface gravity as a main-sequence star? Note that g = GM/R2.

Accepted Answer

Surface gravity: g = GM/R² g_MS/g_AGB = (R_AGB/R_MS)² =

Question 19

Stars with masses similar to the Sun can lose more than 30 percent of their mass before they become white dwarfs.

Accepted Answer

A) True 
 B)False

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

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

What is a planetary nebula?

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

A low-mass main-sequence star's climb up the red giant branch is halted by:

You observed three different star clusters and found that the main-sequence turnoff stars in Cluster 1 had spectral type A,the main-sequence turnoff stars in Cluster 2 had spectral type B,and the main-sequence turnoff stars in Cluster 3 had spectral type G.Which star cluster is the youngest?

A 1 M_$\bigodot$ star in a binary system could create the following chemical element and eject it into the interstellar medium:

Binary stars can evolve to become novae and supernovae because slight differences in mass can mean large differences in main-sequence lifetimes.

Stars evolve primarily because they run out of fuel in their cores.

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

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

In stellar fusion the term "ash" refers to:

About how long will a 2 M_$\bigodot$star live as a main-sequence star?

When a star depletes its core supply of hydrogen, dominates in the core and dominates in the atmosphere.

The Ring Nebula (image below)is a planetary nebula that currently has a radius of 0.4 pc and an expansion velocity of 250 km/s.Approximately how long ago did its parent star die and eject its outer layers?

We can determine the age of a star cluster by measuring the color of the reddest red giant stars in the cluster.

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.

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

When the Sun becomes an AGB star,its radius will be approximately 100 R_$\bigodot$.If its mass at this point will be approximately the same as it is now,how will its surface gravity as an AGB star compare to its present surface gravity as a main-sequence star? Note that g = GM/R².

Stars with masses similar to the Sun can lose more than 30 percent of their mass before they become white dwarfs.

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

Our Place in the Universe

Patterns in the Skymotions of Earth

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

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

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Exam 12: Evolution of Low-Mass Stars

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

What is a planetary nebula?

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

A low-mass main-sequence star's climb up the red giant branch is halted by:

You observed three different star clusters and found that the main-sequence turnoff stars in Cluster 1 had spectral type A,the main-sequence turnoff stars in Cluster 2 had spectral type B,and the main-sequence turnoff stars in Cluster 3 had spectral type G.Which star cluster is the youngest?

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

Binary stars can evolve to become novae and supernovae because slight differences in mass can mean large differences in main-sequence lifetimes.

Stars evolve primarily because they run out of fuel in their cores.

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

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

In stellar fusion the term "ash" refers to:

About how long will a 2 M ⨀\bigodot⨀ star live as a main-sequence star?

When a star depletes its core supply of hydrogen,__________ dominates in the core and __________ dominates in the atmosphere.

The Ring Nebula (image below)is a planetary nebula that currently has a radius of 0.4 pc and an expansion velocity of 250 km/s.Approximately how long ago did its parent star die and eject its outer layers?

We can determine the age of a star cluster by measuring the color of the reddest red giant stars in the cluster.

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.

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

When the Sun becomes an AGB star,its radius will be approximately 100 R ⨀\bigodot⨀ .If its mass at this point will be approximately the same as it is now,how will its surface gravity as an AGB star compare to its present surface gravity as a main-sequence star? Note that g = GM/R2.

Stars with masses similar to the Sun can lose more than 30 percent of their mass before they become white dwarfs.

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

Our Place in the Universe

Patterns in the Skymotions of Earth

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

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

Filters

A 1 M_$\bigodot$ star in a binary system could create the following chemical element and eject it into the interstellar medium:

About how long will a 2 M_$\bigodot$star live as a main-sequence star?

When a star depletes its core supply of hydrogen, dominates in the core and dominates in the atmosphere.

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

When the Sun becomes an AGB star,its radius will be approximately 100 R_$\bigodot$.If its mass at this point will be approximately the same as it is now,how will its surface gravity as an AGB star compare to its present surface gravity as a main-sequence star? Note that g = GM/R².