Question 1

Most of our knowledge of evolutionary tracks comes from stars found in ________.

Accepted Answer

The answer of Most of our knowledge of evolutionary tracks...

Question 2

The "helium flash" occurs at what stage in stellar evolution?

Accepted Answer

A) when the T Tauri bipolar jets shoot out 
B) in the middle of the main sequence stage 
C) red giant 
D) horizontal branch 
E) planetary nebula 
A) when the T Tauri bipolar jets shoot out 
B) in the middle of the main sequence stage 
C) red giant 
D) horizontal branch 
E) planetary nebula

Question 3

As a 4-10 solar mass star leaves the main sequence on its way to becoming a red supergiant,its luminosity:

Accepted Answer

A) decreases. 
B) first decreases, then increases. 
C) increases. 
D) remains roughly constant. 
E) first increases, then decreases. 
A) decreases. 
B) first decreases, then increases. 
C) increases. 
D) remains roughly constant. 
E) first increases, then decreases.

Question 4

What characteristic of a star cluster is used to determine its age?

Accepted Answer

A) the ratio of main sequence to white dwarfs stars 
B) the number of red giants 
C) the faintest stars seen in the cluster 
D) the main sequence turnoff 
E) the total number of stars in the cluster 
A) the ratio of main sequence to white dwarfs stars 
B) the number of red giants 
C) the faintest stars seen in the cluster 
D) the main sequence turnoff 
E) the total number of stars in the cluster

Question 5

Why can we say a star spends its life trying to maintain equilibrium?

Accepted Answer

A star is only stable when the

Question 6

A star is on the horizontal branch of the H-R diagram. Which statement is true?

Accepted Answer

A) It is burning both hydrogen and helium. 
B) It is about to experience the helium flash. 
C) It is burning only helium. 
D) The star is contracting. 
E) The star is about to return to the main sequence. 
A) It is burning both hydrogen and helium. 
B) It is about to experience the helium flash. 
C) It is burning only helium. 
D) The star is contracting. 
E) The star is about to return to the main sequence.

Question 7

The order of evolutionary stages of a star like the Sun would be Main Sequence, giant,planetary nebula, and finally a(n)________.

Accepted Answer

The answer of The order of evolutionary stages of a...

Question 8

While none yet exist, in the very distant future, black dwarfs will comprise the majority ofthe "normal matter" of the universe.

Accepted Answer

A) True 
 B)False

Question 9

All planetary nebulae are slowly expanding spherical disks ejected by red giants, while theirexposed cores appear as white dwarfs.

Accepted Answer

A) True 
 B)False

Question 10

The longest stage in the life cycle of a star is as a(n)________ star.

Accepted Answer

The answer of The longest stage in the life cycle...

Question 11

What spectral type of star that is still around formed longest ago?

Accepted Answer

A) O 
B) A 
C) F 
D) K 
E) M 
A) O 
B) A 
C) F 
D) K 
E) M

Question 12

A high-mass star dies more violently than a low-mass star because:

Accepted Answer

A) it must always end up as a black hole. 
B) it generates more heat and its core eventually collapses very suddenly. 
C) it cannot fuse elements heavier than carbon. 
D) gravity is weakened by its high luminosity. 
E) it is most often found as part of a binary system. 
A) it must always end up as a black hole. 
B) it generates more heat and its core eventually collapses very suddenly. 
C) it cannot fuse elements heavier than carbon. 
D) gravity is weakened by its high luminosity. 
E) it is most often found as part of a binary system.

Question 13

A ten billion year old globular cluster has every star evolved into a giant, with no mainsequence stars left.

Accepted Answer

A) True 
 B)False

Question 14

During various stages of evolution, low mass stars (like the Sun)differ significantly from highmass stars. How and why are the main sequence lifetimes different?

Accepted Answer

High mass stars burn out quick

Question 15

What is the significance of 8 solar masses in stellar evolution?

Accepted Answer

Above 8 solar masses, a high mass star m

Question 16

When a star becomes a red giant, its core expands to a roughly proportional larger size too.

Accepted Answer

A) True 
 B)False

Question 17

How is it possible that life cycles of stars are so well understood and tested, even though theycan take billions of years to happen?

Accepted Answer

Astronomers have observed many

Question 18

Noting the turnoff mass in a star cluster allows you to determine its:

Accepted Answer

A) distance. 
B) radial velocity. 
C) age. 
D) total mass. 
E) number of stars. 
A) distance. 
B) radial velocity. 
C) age. 
D) total mass. 
E) number of stars.

Question 19

Mass transfer in binaries occurs when one giant swells to reach the:

Accepted Answer

A) Chandrasekhar Limit. 
B) Cassini Division. 
C) Hayashi Track. 
D) Roche Lobe. 
E) Herbig-Haro Limit. 
A) Chandrasekhar Limit. 
B) Cassini Division. 
C) Hayashi Track. 
D) Roche Lobe. 
E) Herbig-Haro Limit.

Question 20

The region in the H-R Diagram where evolved, low mass stars are converting helium tocarbon in their cores is the ________.

Accepted Answer

The answer of The region in the H-R Diagram where...

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

Most of our knowledge of evolutionary tracks comes from stars found in ________.

The "helium flash" occurs at what stage in stellar evolution?

As a 4-10 solar mass star leaves the main sequence on its way to becoming a red supergiant,its luminosity:

What characteristic of a star cluster is used to determine its age?

Why can we say a star spends its life trying to maintain equilibrium?

A star is on the horizontal branch of the H-R diagram. Which statement is true?

The order of evolutionary stages of a star like the Sun would be Main Sequence, giant,planetary nebula, and finally a(n)________.

While none yet exist, in the very distant future, black dwarfs will comprise the majority ofthe "normal matter" of the universe.

All planetary nebulae are slowly expanding spherical disks ejected by red giants, while theirexposed cores appear as white dwarfs.

The longest stage in the life cycle of a star is as a(n)________ star.

What spectral type of star that is still around formed longest ago?

A high-mass star dies more violently than a low-mass star because:

A ten billion year old globular cluster has every star evolved into a giant, with no mainsequence stars left.

During various stages of evolution, low mass stars (like the Sun)differ significantly from highmass stars. How and why are the main sequence lifetimes different?

What is the significance of 8 solar masses in stellar evolution?

When a star becomes a red giant, its core expands to a roughly proportional larger size too.

How is it possible that life cycles of stars are so well understood and tested, even though theycan take billions of years to happen?

Noting the turnoff mass in a star cluster allows you to determine its:

Mass transfer in binaries occurs when one giant swells to reach the:

The region in the H-R Diagram where evolved, low mass stars are converting helium tocarbon in their cores is the ________.

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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