Question 1

You observe a low-mass helium white dwarf. What can you conclude?

Accepted Answer

A) It is over 100 billion years old. 
B) It will soon be a planetary nebula. 
C) It is part of a binary star system. 
D) Its core is mostly carbon. 
E) It was once a blue supergiant. 
A) It is over 100 billion years old. 
B) It will soon be a planetary nebula. 
C) It is part of a binary star system. 
D) Its core is mostly carbon. 
E) It was once a blue supergiant.

Question 2

Describe the helium flash and why it occurs.

Accepted Answer

When the core of a red giant has reached

Question 3

The Roche lobe of a star in a binary star system:

Accepted Answer

A) resembles the ear of Edouard Roche, a French mathematician. 
B) is, in terms of the star's gravity, its "zone of influence." 
C) is the part of a rapidly rotating star that will eventually spin away to form planets. 
D) is the accretion disk around the companion star. 
E) leads to formation of rings, like around the jovian planets. 
A) resembles the ear of Edouard Roche, a French mathematician. 
B) is, in terms of the star's gravity, its "zone of influence." 
C) is the part of a rapidly rotating star that will eventually spin away to form planets. 
D) is the accretion disk around the companion star. 
E) leads to formation of rings, like around the jovian planets.

Question 4

Modern astronomers have observed the complete life cycle for many stars, making stellarevolution one of the best-tested astronomical theories.

Accepted Answer

A) True 
 B)False

Question 5

For our Sun, the production of carbon will be the end of its nucleosynthesis.

Accepted Answer

A) True 
 B)False

Question 6

Refer to the figure above. What is the name of the path between the points labeled 11 and12?

Accepted Answer

A) planetary nebula 
B) red giant branch 
C) horizontal branch 
D) asymptotic giant branch 
E) white dwarf 
A) planetary nebula 
B) red giant branch 
C) horizontal branch 
D) asymptotic giant branch 
E) white dwarf

Question 7

Give evidence that magnetism plays a role in planetary nebula formation.

Accepted Answer

Most of them are bipolar ejections, and

Question 8

Which of the following elements contained in your body is NOT formed in the cores of starsduring thermonuclear fusion?

Accepted Answer

A) hydrogen 
B) carbon 
C) calcium 
D) iron 
E) aluminum 
A) hydrogen 
B) carbon 
C) calcium 
D) iron 
E) aluminum

Question 9

For binary star systems where the stars are separated by more than 1000 stellar radii, masstransfer is not an issue.

Accepted Answer

A) True 
 B)False

Question 10

Refer to the figure above. What is the name of the path between the points labeled 8 and 9?

Accepted Answer

A) planetary nebula 
B) red giant branch 
C) horizontal branch 
D) asymptotic giant branch 
E) white dwarf 
A) planetary nebula 
B) red giant branch 
C) horizontal branch 
D) asymptotic giant branch 
E) white dwarf

Question 11

What is the source of the large dust shells seen around some red giants and red supergiants?

Accepted Answer

A) leftover material from their formation 
B) debris left behind by a supernova 
C) material from winds from these same stars 
D) debris left behind by passing comets 
E) star-forming molecular clouds 
A) leftover material from their formation 
B) debris left behind by a supernova 
C) material from winds from these same stars 
D) debris left behind by passing comets 
E) star-forming molecular clouds

Question 12

What are black dwarfs?

Accepted Answer

A) the lowest mass main sequence stars 
B) the end result of massive star evolution 
C) objects that are not quite massive enough to be stars 
D) pulsars that have slowed down and stopped spinning 
E) cooled off white dwarfs that no longer glow visibly 
A) the lowest mass main sequence stars 
B) the end result of massive star evolution 
C) objects that are not quite massive enough to be stars 
D) pulsars that have slowed down and stopped spinning 
E) cooled off white dwarfs that no longer glow visibly

Question 13

Which of the following is true regarding planetary nebulae?

Accepted Answer

A) Some are spherical, but most have bipolar structure. 
B) They are the result of the mass loss during the main sequence stage of the most massive stars. 
C) They are the rings of material surrounding newly formed stars that will eventually form theplanetary systems. 
D) They are the ejected envelopes of highly evolved brown dwarf stars. 
E) They are the coronas surrounding most blue stragglers. 
A) Some are spherical, but most have bipolar structure. 
B) They are the result of the mass loss during the main sequence stage of the most massive stars. 
C) They are the rings of material surrounding newly formed stars that will eventually form theplanetary systems. 
D) They are the ejected envelopes of highly evolved brown dwarf stars. 
E) They are the coronas surrounding most blue stragglers.

Question 14

Isolated main sequence stars as massive as 10 to 12 times the mass of the Sun may stillmanage to avoid going supernova. Why?

Accepted Answer

A) because they can also have strong stellar winds 
B) because about half that mass will be contained in the carbon core 
C) because they would be classified as brown dwarfs 
D) because these stars will eject at least 4 solar masses in the planetary nebula stage 
E) because their masses will decrease as they fuse heavy elements into lighter elements in theircores 
A) because they can also have strong stellar winds 
B) because about half that mass will be contained in the carbon core 
C) because they would be classified as brown dwarfs 
D) because these stars will eject at least 4 solar masses in the planetary nebula stage 
E) because their masses will decrease as they fuse heavy elements into lighter elements in theircores

Question 15

What is peculiar about Sirius based on historical records?

Accepted Answer

Records from 100 B.C. to 200 A

Question 16

The order of evolutionary stages of a star like the Sun would be Main Sequence, giant,planetary nebula, and finally:

Accepted Answer

A) hypernova. 
B) neutron star. 
C) white dwarf. 
D) nova. 
E) black hole. 
A) hypernova. 
B) neutron star. 
C) white dwarf. 
D) nova. 
E) black hole.

Question 17

When helium fusion begins in a one solar mass main star, it begins gradually, with this rateslowly increasing over time.

Accepted Answer

A) True 
 B)False

Question 18

During the hydrogen shell-burning phase:

Accepted Answer

A) the star grows more luminous. 
B) the star becomes less luminous. 
C) helium is burning in the core. 
D) the core is expanding. 
E) hydrogen is burning in the central core. 
A) the star grows more luminous. 
B) the star becomes less luminous. 
C) helium is burning in the core. 
D) the core is expanding. 
E) hydrogen is burning in the central core.

Question 19

The brightest stars in a young open cluster will be:

Accepted Answer

A) massive blue stars at the top left on the H-R diagram. 
B) red T Tauri stars still heading for the main sequence. 
C) red giants that are fusing helium into carbon. 
D) yellow giants like our Sun, but much larger. 
E) the core stars of planetary nebulae. 
A) massive blue stars at the top left on the H-R diagram. 
B) red T Tauri stars still heading for the main sequence. 
C) red giants that are fusing helium into carbon. 
D) yellow giants like our Sun, but much larger. 
E) the core stars of planetary nebulae.

Question 20

What is the unusual result of mass transfer in the Algol binary system?

Accepted Answer

A) a helium white dwarf 
B) a carbon white dwarf 
C) a black dwarf 
D) a red dwarf 
E) a brown dwarf 
A) a helium white dwarf 
B) a carbon white dwarf 
C) a black dwarf 
D) a red dwarf 
E) a brown dwarf

Exam 20: Stellar Evolution: The Life and Death of a Star

You observe a low-mass helium white dwarf. What can you conclude?

Describe the helium flash and why it occurs.

The Roche lobe of a star in a binary star system:

Modern astronomers have observed the complete life cycle for many stars, making stellarevolution one of the best-tested astronomical theories.

For our Sun, the production of carbon will be the end of its nucleosynthesis.

Refer to the figure above. What is the name of the path between the points labeled 11 and12?

Give evidence that magnetism plays a role in planetary nebula formation.

Which of the following elements contained in your body is NOT formed in the cores of starsduring thermonuclear fusion?

For binary star systems where the stars are separated by more than 1000 stellar radii, masstransfer is not an issue.

Refer to the figure above. What is the name of the path between the points labeled 8 and 9?

What is the source of the large dust shells seen around some red giants and red supergiants?

What are black dwarfs?

Which of the following is true regarding planetary nebulae?

Isolated main sequence stars as massive as 10 to 12 times the mass of the Sun may stillmanage to avoid going supernova. Why?

What is peculiar about Sirius based on historical records?

The order of evolutionary stages of a star like the Sun would be Main Sequence, giant,planetary nebula, and finally:

When helium fusion begins in a one solar mass main star, it begins gradually, with this rateslowly increasing over time.

During the hydrogen shell-burning phase:

The brightest stars in a young open cluster will be:

What is the unusual result of mass transfer in the Algol binary system?

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information From the Cosmos

Spectroscopy: the Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earths Sister Planet

Mars: a Near Miss for Life

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants, Dwarfs, and the Main Sequence

The Interstellar Medium: Gas and Dust Among the Stars

Star Formation: a Traumatic Birth

Stellar Explosions: Novae, Supernovae, and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: a Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

Life in the Universe: Are We Alone

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