Question 1

Why does neutron capture work?

Accepted Answer

A)  Neutrons have no repulsive barrier to overcome in combining with positively charged nuclei.
B)  Neutrinos, because of their low mass and high speed, easily penetrate nuclei.
C)  Single protons have little repulsion to heavy nuclei and easily fuse with them.
D)  Photodisintegration makes many alpha particles, available for capture by nuclei.
E)  Neutronization captures all the protons and electrons.

Question 2

What can you conclude about a Type I supernova?

Accepted Answer

A)  It was originally a low-mass star.
B)  It was originally a high mass star.
C)  Its spectrum will show large amounts of hydrogen.
D)  Its core was mostly iron.
E)  The star never reached the Chandrasekhar Limit.

Question 3

Type I supernovae are NOT:

Accepted Answer

A)  products of mass transfer.
B)  created by the mass of the white dwarf exceeding Chandrasekhar's Limit.
C)  rich in hydrogen from the outer envelope of the collapsed star.
D)  brighter than Type II supernovae.
E)  created by carbon detonation.

Question 4

The Chandrasekhar mass limit is:

Accepted Answer

A)  .08 solar masses.
B)  .4 solar masses.
C)  1.4 solar masses.
D)  3 solar masses.
E)  8 solar masses.

Question 5

What role does the main sequence mass of the star play in the formation of heavy elements inthe giant stage?

Accepted Answer

Basically the greater the mass of the at...

Question 6

If a white dwarf gains sufficient mass, it can become a:

Accepted Answer

A)  brown dwarf.
B)  Type II supernova.
C)  Type I supernova.
D)  planetary nebula.
E)  black dwarf.

Question 7

What direct evidence do astronomers have that supports the heavy element formation instars?

Accepted Answer

A)  the presence of technetium in giant star spectra
B)  observed elemental abundances
C)  gamma-ray emissions from decay of cobalt 56 in supernovae
D)  light curves of type-I supernovae
E)  All of the above are evidence of this.

Question 8

Will our Sun become a supernova? Why?

Accepted Answer

No, it is not in a close binar...

Question 9

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

Question 10

Which of these does NOT depend on a close binary system to occur?

Accepted Answer

A)  a nova
B)  a Type I supernova
C)  a Type II supernova
D)  All of these need mass transfer to occur.
E)  None of these depend on mass transfer.

Question 11

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

Accepted Answer

Type I supernovae have very little hydro...

Question 12

Unlike supernovae, novae can explode more than once, increasing their luminosity bythousands of times.

Accepted Answer

A) True 
 B)False

Question 13

Which statement about young stars is FALSE?

Accepted Answer

A)  They contain a larger fraction of heavy elements than previous generations.
B)  They are born in a dustier environment than earlier generations.
C)  They are more likely to have planets forming with them than earlier generations.
D)  The high mass stars will be more likely to produce heavier elements as they evolve.
E)  Being young, they will have more pure hydrogen than earlier generations.

Question 14

Supernova remnants differ from star forming regions because, although there is ionizedhydrogen in both, supernova remnants:

Accepted Answer

A)  don't look like star forming regions.
B)  are much bigger than star forming regions.
C)  are located far from star forming regions.
D)  are more diffuse than star forming regions.
E)  contain no ionizing stars.

Question 15

What is the importance of 1.4 solar masses in stellar evolution?

Accepted Answer

1.4 solar masses is the Chandrasekhar Li...

Question 16

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

Accepted Answer

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

Question 17

In order of visual luminosity at the start, which is most luminous?

Accepted Answer

A)  a red supergiant
B)  a planetary nebula
C)  a nova
D)  a Type I supernova
E)  a Type II supernova

Question 18

Which of these events is NOT possible?

Accepted Answer

A)  low-mass stars swelling up to produce planetary nebulae
B)  red giants exploding as Type II supernovae
C)  close binary stars producing recurrent novae explosions
D)  white dwarfs and companion stars producing recurrent Type I supernova events
E)  a white dwarf being found in the center of a planetary nebula

Question 19

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 20

Iron is the most stably bonded atomic nucleus.

Accepted Answer

A) True 
 B)False

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

Which of these does NOT depend on a close binary system to occur?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Supernova remnants differ from star forming regions because, although there is ionizedhydrogen in both, supernova remnants:

Correct AnswerverifiedShow Answer

The Chandrasekhar mass limit is:

Correct AnswerverifiedShow Answer

Iron is the most stably bonded atomic nucleus.

Correct AnswerverifiedShow Answer

Will our Sun become a supernova? Why?

Correct AnswerverifiedNo, it is not in a close binar...View AnswerShow Answer

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

Correct AnswerverifiedIron is the most tightly bonded of all n...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

Which statement about young stars is FALSE?

Correct AnswerverifiedShow Answer

What is the importance of 1.4 solar masses in stellar evolution?

Correct Answerverified1.4 solar masses is the Chandrasekhar Li...View AnswerShow Answer

If a white dwarf gains sufficient mass, it can become a:

Correct AnswerverifiedShow Answer

What direct evidence do astronomers have that supports the heavy element formation instars?

Correct AnswerverifiedShow Answer

In order of visual luminosity at the start, which is most luminous?

Correct AnswerverifiedShow Answer

Why does neutron capture work?

Correct AnswerverifiedShow Answer

What role does the main sequence mass of the star play in the formation of heavy elements inthe giant stage?

Correct AnswerverifiedBasically the greater the mass of the at...View AnswerShow Answer

Type I supernovae are NOT:

Correct AnswerverifiedShow Answer

Which of these events is NOT possible?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedType I supernovae have very little hydro...View AnswerShow Answer

Unlike supernovae, novae can explode more than once, increasing their luminosity bythousands of times.

Correct AnswerverifiedShow Answer

What can you conclude about a Type I supernova?

Correct AnswerverifiedShow Answer

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No, it is not in a close binar...
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Iron is the most tightly bonded of all n...
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1.4 solar masses is the Chandrasekhar Li...
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Basically the greater the mass of the at...
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Type I supernovae have very little hydro...
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Correct Answer
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Correct Answer
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