Question 1

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

Question 2

What are the three major mass ranges for stars?

Accepted Answer

The three mass ranges are: low-mass star

Question 3

Explain why stars are able to lose mass as they expand to red giant size.

Accepted Answer

As the star expands,its mass is spread o

Question 4

What types of fusion are occurring in an asymptotic giant branch (AGB) star, where is each type located, and what are the products of each type?

Accepted Answer

Helium is fusing into carbon i

Question 5

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

A)  There will be an equal amount of energy produced. 
B)  There will be less energy produced. 
C)  There will be more energy produced. 
D)  There will be more energy produced only if the star's mass exceeds that of the Sun. 
E)  There will be less energy produced only if the star's mass is less than that of the Sun. 
A)  There will be an equal amount of energy produced. 
B)  There will be less energy produced. 
C)  There will be more energy produced. 
D)  There will be more energy produced only if the star's mass exceeds that of the Sun. 
E)  There will be less energy produced only if the star's mass is less than that of the Sun.

Question 6

Stars evolve primarily because

Accepted Answer

A)  they convert all their mass to energy. 
B)  they lose all their mass into space. 
C)  their core temperatures decrease steadily as they evolve. 
D)  they use up the fuel in their cores. 
E)  they run out of rotational energy. 
A)  they convert all their mass to energy. 
B)  they lose all their mass into space. 
C)  their core temperatures decrease steadily as they evolve. 
D)  they use up the fuel in their cores. 
E)  they run out of rotational energy.

Question 7

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. 
E)  an explosion that destroys the star. 
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. 
E)  an explosion that destroys the star.

Question 8

Which star spends the longest time as a main-sequence star?

Accepted Answer

A)  0.5 MSUN 
B)  1 MSUN 
C)  3 MSUN 
D)  6 MSUN 
E)  10 MSUN 
A)  0.5 MSUN 
B)  1 MSUN 
C)  3 MSUN 
D)  6 MSUN 
E)  10 MSUN

Question 9

A star like the Sun will lose ________ of its mass before it evolves to become a white dwarf.

Accepted Answer

A)  almost none 
B)  about half 
C)  about 90% 
D)  the vast majority (about 99%) 
E)  absolutely none 
A)  almost none 
B)  about half 
C)  about 90% 
D)  the vast majority (about 99%) 
E)  absolutely none

Question 10

A particular asymptotic giant branch star has approximately the same mass as the Sun but 100 times its radius.Compared with the Sun, what is the escape velocity from that star?

Accepted Answer

A)  0.01 times that of the Sun 
B)  0.1 times that of the Sun 
C)  the same as that of the Sun 
D)  10 times that of the Sun 
E)  100 times that of the Sun 
A)  0.01 times that of the Sun 
B)  0.1 times that of the Sun 
C)  the same as that of the Sun 
D)  10 times that of the Sun 
E)  100 times that of the Sun

Question 11

A Type Ia supernova occurs when a white dwarf exceeds a mass of

Accepted Answer

A)  0.8 MSUN. 
B)  1.4 MSUN. 
C)  2.3 MSUN. 
D)  5.4 MSUN. 
E)  10 MSUN. 
A)  0.8 MSUN. 
B)  1.4 MSUN. 
C)  2.3 MSUN. 
D)  5.4 MSUN. 
E)  10 MSUN.

Question 12

Asymptotic giant branch stars have ________ luminosities, ________ radii, and ________ escape velocities.

Accepted Answer

A)  large; large; large 
B)  large; small; large 
C)  large; large; small 
D)  small; large; small 
E)  small; small; large 
A)  large; large; large 
B)  large; small; large 
C)  large; large; small 
D)  small; large; small 
E)  small; small; large

Question 13

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

Accepted Answer

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

Question 14

What are two ways that Type Ia supernovae can be produced?

Accepted Answer

A)  mass transfer and stellar mergers 
B)  helium flash and stellar mergers 
C)  mass transfer and helium flash 
D)  helium fusion and mass transfer 
E)  iron fusion and mass transfer 
A)  mass transfer and stellar mergers 
B)  helium flash and stellar mergers 
C)  mass transfer and helium flash 
D)  helium fusion and mass transfer 
E)  iron fusion and mass transfer

Question 15

Describe the helium flash that occurs when helium fusion ignites in the core of a red giant star.

Accepted Answer

Once the helium nuclei reach a high enou

Question 16

What is the shortest phase of evolution for a one solar mass star that we can visibly see?

Accepted Answer

The planetary nebula phase is the shorte

Question 17

What factor is most important in determining a star's position on the main sequence and its subsequent evolution?

Accepted Answer

A)  temperature 
B)  pressure 
C)  mass 
D)  radius 
E)  color 
A)  temperature 
B)  pressure 
C)  mass 
D)  radius 
E)  color

Question 18

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

Accepted Answer

A)  The radius is decreasing. 
B)  The radius is increasing. 
C)  The star is getting hotter. 
D)  The star is losing mass. 
E)  The star is rotating more slowly. 
A)  The radius is decreasing. 
B)  The radius is increasing. 
C)  The star is getting hotter. 
D)  The star is losing mass. 
E)  The star is rotating more slowly.

Question 19

The following figure illustrates the

Accepted Answer

A)  proton-proton chain. 
B)  process of electron-degeneracy. 
C)  beryllium decay process. 
D)  alpha decay chain. 
E)  triple-alpha process. 
A)  proton-proton chain. 
B)  process of electron-degeneracy. 
C)  beryllium decay process. 
D)  alpha decay chain. 
E)  triple-alpha process.

Question 20

What is "degenerate" in the degenerate core of a white dwarf?

Accepted Answer

Only the electrons a

Exam 16: Evolution of Low-Mass Stars

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

What are the three major mass ranges for stars?

Explain why stars are able to lose mass as they expand to red giant size.

What types of fusion are occurring in an asymptotic giant branch (AGB) star, where is each type located, and what are the products of each type?

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

Stars evolve primarily because

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

Which star spends the longest time as a main-sequence star?

A star like the Sun will lose ________ of its mass before it evolves to become a white dwarf.

A particular asymptotic giant branch star has approximately the same mass as the Sun but 100 times its radius.Compared with the Sun, what is the escape velocity from that star?

A Type Ia supernova occurs when a white dwarf exceeds a mass of

Asymptotic giant branch stars have ________ luminosities, ________ radii, and ________ escape velocities.

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

What are two ways that Type Ia supernovae can be produced?

Describe the helium flash that occurs when helium fusion ignites in the core of a red giant star.

What is the shortest phase of evolution for a one solar mass star that we can visibly see?

What factor is most important in determining a star's position on the main sequence and its subsequent evolution?

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

The following figure illustrates the

What is "degenerate" in the degenerate core of a white dwarf?

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Formation of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Planetary Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

The Interstellar Medium and Star Formation

Evolution of High-Mass Stars

Relativity and Black Holes

Galaxies

The Milky Waya Normal Spiral Galaxy

The Expanding Universe

Cosmology

Large-Scale Structure in the Universe

Life

Filters

Asymptotic giant branch stars have luminosities, radii, and escape velocities.

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