Question 1

When a star is stably fusing helium in its core, it is a ________ star.

Accepted Answer

A star that is stably fusing helium in its core is on the horizontal branch of the Hertzsprung-Russell diagram.

Question 2

When matter is packed so tightly together that quantum physics will not allow the electrons to get any closer, it is called

Accepted Answer

Electron-degenerate matter occurs when electrons are packed so tightly that quantum mechanics prevents them from being compressed further, a state often found in white dwarfs.

Question 3

During evolutionary phase A in the figure shown below, the star is ________.In evolutionary phase B, it is ________.

Accepted Answer

The answer of During evolutionary phase A in the figure...

Question 4

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

Accepted Answer

Helium burns in the core of a horizontal branch star via the triple-alpha reaction, which fuses three helium nuclei to form carbon.

Question 5

The following figure illustrates the

Accepted Answer

The answer of The following figure illustrates the 
...

Question 6

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

Accepted Answer

As the core of a red giant contracts, it heats up, which increases the rate of hydrogen shell burning around the core.

Question 7

As a subgiant star becomes a red giant, its luminosity increases while its temperature remains approximately constant.What does this mean?

Accepted Answer

As a star's luminosity increases while its temperature remains constant, the increase in luminosity must be due to an increase in the star's radius, according to the Stefan-Boltzmann law.

Question 8

A 1-M_SUN red giant star's energy comes from

Accepted Answer

A 1-M_SUN red giant star has exhausted hydrogen in its core, so energy is produced by hydrogen burning to helium in a shell surrounding the core.

Question 9

A low-mass star that burns helium in its core and hydrogen in a shell surrounding the core is ________ than a similar star that burns hydrogen only ________.

Accepted Answer

The answer of A low-mass star that burns helium in...

Question 10

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

Accepted Answer

The surface temperature of a star during the horizontal branch phase is primarily determined by its mass and chemical composition, which influence the star's energy output and structure.

Question 11

When a star burns hydrogen in a shell, how does the energy released compare with when the star burned hydrogen in the core?

Accepted Answer

When a star burns hydrogen in a shell, it is typically in the red giant phase, where the energy output is greater due to the larger surface area and increased luminosity compared to when it was burning hydrogen in the core.

Question 12

If there were mixing processes in a main-sequence star with a radiative zone (there aren't) that churned up all the material in the interior, we would expect that the main-sequence lifetime would be ________ because ________.

Accepted Answer

Mixing processes would bring fresh hydrogen into the core, allowing the star to sustain nuclear fusion for a longer period, thus extending its main-sequence lifetime.

Question 13

________ keeps the core of a red giant star from collapsing.

Accepted Answer

Degenerate pressure from electrons, also known as electron degeneracy pressure, prevents the core of a red giant star from collapsing by providing a quantum mechanical pressure that is independent of temperature.

Question 14

Place the evolutionary stages shown in the figure below in order from earliest to latest.

Accepted Answer

The answer of Place the evolutionary stages shown in the...

Question 15

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

Electron-degeneracy pressure is independent of temperature, so when helium fusion begins, the temperature rises rapidly without affecting the pressure, leading to a runaway reaction known as the helium flash.

Question 16

Degenerate refers to a state of matter at

Accepted Answer

Degenerate matter occurs at high densities where particles are packed closely together, such as in white dwarfs or neutron stars, where quantum mechanical effects dominate.

Question 17

When a spectral-type G2 star like the Sun leaves the main sequence, its

Accepted Answer

When a G2 star like the Sun leaves the main sequence, it becomes a red giant. During this phase, its luminosity increases due to the expansion of its outer layers, while its surface temperature decreases as the star's surface cools.

Question 18

The figure below depicts helium fusion in a late-stage star with certain elements labeled A, B, and C.What are these elements, in the order A, B, C?

Accepted Answer

The answer of The figure below depicts helium fusion in...

Question 19

Using the figure shown below, identify the star with the smallest radius.

Accepted Answer

The answer of Using the figure shown below, identify the...

Question 20

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

During the horizontal branch phase, a low-mass star has two separate regions of nuclear burning: helium fusion in the core and hydrogen fusion in a shell surrounding the core.

Quiz 16: Evolution of Low-Mass Stars

When a star is stably fusing helium in its core, it is a ________ star.

When matter is packed so tightly together that quantum physics will not allow the electrons to get any closer, it is called

During evolutionary phase A in the figure shown below, the star is .In evolutionary phase B, it is .

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

The following figure illustrates the

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

As a subgiant star becomes a red giant, its luminosity increases while its temperature remains approximately constant.What does this mean?

A 1-M_SUN red giant star's energy comes from

A low-mass star that burns helium in its core and hydrogen in a shell surrounding the core is than a similar star that burns hydrogen only .

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

When a star burns hydrogen in a shell, how does the energy released compare with when the star burned hydrogen in the core?

If there were mixing processes in a main-sequence star with a radiative zone (there aren't) that churned up all the material in the interior, we would expect that the main-sequence lifetime would be because .

________ keeps the core of a red giant star from collapsing.

Place the evolutionary stages shown in the figure below in order from earliest to latest.

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

Degenerate refers to a state of matter at

When a spectral-type G2 star like the Sun leaves the main sequence, its

The figure below depicts helium fusion in a late-stage star with certain elements labeled A, B, and C.What are these elements, in the order A, B, C?

Using the figure shown below, identify the star with the smallest radius.

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

Quiz 16: Evolution of Low-Mass Stars

When a star is stably fusing helium in its core, it is a ________ star.

When matter is packed so tightly together that quantum physics will not allow the electrons to get any closer, it is called

During evolutionary phase A in the figure shown below, the star is ________.In evolutionary phase B, it is ________.

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

The following figure illustrates the

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

As a subgiant star becomes a red giant, its luminosity increases while its temperature remains approximately constant.What does this mean?

A 1-MSUN red giant star's energy comes from

A low-mass star that burns helium in its core and hydrogen in a shell surrounding the core is ________ than a similar star that burns hydrogen only ________.

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

When a star burns hydrogen in a shell, how does the energy released compare with when the star burned hydrogen in the core?

If there were mixing processes in a main-sequence star with a radiative zone (there aren't) that churned up all the material in the interior, we would expect that the main-sequence lifetime would be ________ because ________.

________ keeps the core of a red giant star from collapsing.

Place the evolutionary stages shown in the figure below in order from earliest to latest.

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

Degenerate refers to a state of matter at

When a spectral-type G2 star like the Sun leaves the main sequence, its

The figure below depicts helium fusion in a late-stage star with certain elements labeled A, B, and C.What are these elements, in the order A, B, C?

Using the figure shown below, identify the star with the smallest radius.

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

During evolutionary phase A in the figure shown below, the star is .In evolutionary phase B, it is .

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

A 1-M_SUN red giant star's energy comes from

A low-mass star that burns helium in its core and hydrogen in a shell surrounding the core is than a similar star that burns hydrogen only .

If there were mixing processes in a main-sequence star with a radiative zone (there aren't) that churned up all the material in the interior, we would expect that the main-sequence lifetime would be because .