Question 1

Why does iron formation cause a high mass star to "have a heart attack"?

Accepted Answer

Iron is the most tightly bonded of all n

Question 2

What made supernova 1987a so useful to study?

Accepted Answer

A)  We saw direct evidence of nickel to iron decay in its light curve. 
B)  Its progenitor had been observed previously. 
C)  In the Large Magellanic Cloud, we already knew its distance. 
D)  It occurred after new telescopes, such as Hubble, could observe it very closely. 
E)  All of the above are correct. 
A)  We saw direct evidence of nickel to iron decay in its light curve. 
B)  Its progenitor had been observed previously. 
C)  In the Large Magellanic Cloud, we already knew its distance. 
D)  It occurred after new telescopes, such as Hubble, could observe it very closely. 
E)  All of the above are correct.

Question 3

Iron nuclei are the most tightly bound nuclei,which is why their production leads to type II supernovae.

Accepted Answer

A) True 
 B)False

Question 4

At temperatures of ________ K,photons can split apart nuclei until only protons and neutrons are left in photodisintegration.

Accepted Answer

A)  ten million 
B)  100 million 
C)  one billion 
D)  ten billion 
E)  one hundred billion 
A)  ten million 
B)  100 million 
C)  one billion 
D)  ten billion 
E)  one hundred billion

Question 5

What evidence is there that supernovae really have occurred?

Accepted Answer

A)  Crab Nebula 
B)  supernova remnants 
C)  existence of heavy radioactive elements in nature 
D)  observations of the actual explosions 
E)  All of the above. 
A)  Crab Nebula 
B)  supernova remnants 
C)  existence of heavy radioactive elements in nature 
D)  observations of the actual explosions 
E)  All of the above.

Question 6

The supernova that formed M-1,the Crab Nebula,was observed in:

Accepted Answer

A)  1572 AD by Tycho Brahe. 
B)  1604 AD by Johannes Kepler. 
C)  1054 AD by Chinese and Middle Eastern astronomers. 
D)  1006 by observers in the southern hemisphere. 
E)  about 9,000 BC by all our ancestors. 
A)  1572 AD by Tycho Brahe. 
B)  1604 AD by Johannes Kepler. 
C)  1054 AD by Chinese and Middle Eastern astronomers. 
D)  1006 by observers in the southern hemisphere. 
E)  about 9,000 BC by all our ancestors.

Question 7

The core of a highly evolved high mass star is a little larger than:

Accepted Answer

A)  our solar system. 
B)  our Sun. 
C)  Jupiter. 
D)  Earth. 
E)  a white dwarf. 
A)  our solar system. 
B)  our Sun. 
C)  Jupiter. 
D)  Earth. 
E)  a white dwarf.

Question 8

As seen in 1987,when two silicon 28 nuclei fuse,or when seven alpha particles are added to a Si-28 nucleus,the initial result in either case is:

Accepted Answer

A)  the shedding of bipolar planetary nebula shells. 
B)  a nova explosion. 
C)  iron 56. 
D)  cobalt 56. 
E)  nickel 56. 
A)  the shedding of bipolar planetary nebula shells. 
B)  a nova explosion. 
C)  iron 56. 
D)  cobalt 56. 
E)  nickel 56.

Question 9

Most of the energy of the supernova is carried outward via a flood of:

Accepted Answer

A)  gamma rays. 
B)  helium nuclei. 
C)  protons. 
D)  neutrinos. 
E)  positrons. 
A)  gamma rays. 
B)  helium nuclei. 
C)  protons. 
D)  neutrinos. 
E)  positrons.

Question 10

Type II supernovae have little hydrogen in their spectra; it had been used up already.

Accepted Answer

A) True 
 B)False

Question 11

The heaviest nuclei of all are formed:

Accepted Answer

A)  in the horizontal branch. 
B)  in dense white dwarfs. 
C)  during nova explosions. 
D)  in the ejection of matter in the planetary nebula. 
E)  in the core collapse that set the stage of type II supernovae. 
A)  in the horizontal branch. 
B)  in dense white dwarfs. 
C)  during nova explosions. 
D)  in the ejection of matter in the planetary nebula. 
E)  in the core collapse that set the stage of type II supernovae.

Question 12

For a nova to occur,the system must have already been a(n):

Accepted Answer

A)  astrometric binary. 
B)  detached binary. 
C)  spectroscopic binary. 
D)  mass-transfer binary. 
E)  eclipsing binary. 
A)  astrometric binary. 
B)  detached binary. 
C)  spectroscopic binary. 
D)  mass-transfer binary. 
E)  eclipsing binary.

Question 13

What are two differences observed between type I and type II supernovae?

Accepted Answer

Type I supernovae have very little hydro

Question 14

The spectra of the youngest stars show the most heavy elements present.

Accepted Answer

A) True 
 B)False

Question 15

Which of these is the likely progenitor of a type II supernova?

Accepted Answer

A)  a mass-transfer binary, with the white dwarf already at 1.3 solar masses 
B)  a contact binary, with the neutron star at 2.3 solar masses 
C)  an evolved red giant which is just starting to make silicon in its core 
D)  two white dwarfs in a contact binary system 
E)  an evolved blue supergiant that is about to experience the helium flash 
A)  a mass-transfer binary, with the white dwarf already at 1.3 solar masses 
B)  a contact binary, with the neutron star at 2.3 solar masses 
C)  an evolved red giant which is just starting to make silicon in its core 
D)  two white dwarfs in a contact binary system 
E)  an evolved blue supergiant that is about to experience the helium flash

Question 16

A 20 solar mass star will stay on the main sequence for 10 million years,yet its iron core can exist for only a:

Accepted Answer

A)  day. 
B)  week. 
C)  month. 
D)  year. 
E)  century. 
A)  day. 
B)  week. 
C)  month. 
D)  year. 
E)  century.

Question 17

An object in the sky brightens suddenly,but shows no hydrogen lines in its spectrum.It is most likely a(n):

Accepted Answer

A)  comet. 
B)  type I supernova. 
C)  type II supernova. 
D)  asteroid impact. 
E)  stellar collision. 
A)  comet. 
B)  type I supernova. 
C)  type II supernova. 
D)  asteroid impact. 
E)  stellar collision.

Question 18

Which of these is the likely progenitor of a type I supernova?

Accepted Answer

A)  a mass-transfer binary, with the white dwarf already at 1.3 solar masses 
B)  a contact binary, with the neutron star at 2.3 solar masses 
C)  an evolved red giant which is just starting to make silicon in its core 
D)  an evolved blue supergiant that is about to experience the helium flash 
E)  a helium-neon white dwarf 
A)  a mass-transfer binary, with the white dwarf already at 1.3 solar masses 
B)  a contact binary, with the neutron star at 2.3 solar masses 
C)  an evolved red giant which is just starting to make silicon in its core 
D)  an evolved blue supergiant that is about to experience the helium flash 
E)  a helium-neon white dwarf

Question 19

Because they all involve formation of iron in cores of massive stars,all type II supernovae are equally luminous.

Accepted Answer

A) True 
 B)False

Question 20

The Chandrasekhar mass limit is:

Accepted Answer

A)  0.08 solar masses. 
B)  0.4 solar masses. 
C)  1.4 solar masses. 
D)  3 solar masses. 
E)  8 solar masses. 
A)  0.08 solar masses. 
B)  0.4 solar masses. 
C)  1.4 solar masses. 
D)  3 solar masses. 
E)  8 solar masses.

Exam 21: Stellar Explosions: Novae,Supernovae,and the Formation of the Elements

Why does iron formation cause a high mass star to "have a heart attack"?

What made supernova 1987a so useful to study?

Iron nuclei are the most tightly bound nuclei,which is why their production leads to type II supernovae.

At temperatures of ________ K,photons can split apart nuclei until only protons and neutrons are left in photodisintegration.

What evidence is there that supernovae really have occurred?

The supernova that formed M-1,the Crab Nebula,was observed in:

The core of a highly evolved high mass star is a little larger than:

As seen in 1987,when two silicon 28 nuclei fuse,or when seven alpha particles are added to a Si-28 nucleus,the initial result in either case is:

Most of the energy of the supernova is carried outward via a flood of:

Type II supernovae have little hydrogen in their spectra; it had been used up already.

The heaviest nuclei of all are formed:

For a nova to occur,the system must have already been a(n):

What are two differences observed between type I and type II supernovae?

The spectra of the youngest stars show the most heavy elements present.

Which of these is the likely progenitor of a type II supernova?

A 20 solar mass star will stay on the main sequence for 10 million years,yet its iron core can exist for only a:

An object in the sky brightens suddenly,but shows no hydrogen lines in its spectrum.It is most likely a(n):

Which of these is the likely progenitor of a type I supernova?

Because they all involve formation of iron in cores of massive stars,all type II supernovae are equally luminous.

The Chandrasekhar mass limit is:

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: Earth's 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 Evolution: The Life and Death of a Star

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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