Question 1

Like most pulsars, the Crab Nebula neutron star is known only by its radio pulses.

Accepted Answer

A) True 
 B)False

Question 2

What compelling evidence links pulsars to neutron stars?

Accepted Answer

A)   Both pulsars and neutron stars can be found in globular star clusters.
B)   Pulsars are known to evolve into neutron stars.
C)   Only a small, very dense source could rotate that rapidly without flying apart.
D)   Pulsars are always found in binary systems with neutron stars.
E)   Both pulsars and neutron stars have been discovered near the Sun.

Question 3

Except for hydrogen and most of the helium, all the elements have been formed through stellar nucleosynthesis.

Accepted Answer

A) True 
 B)False

Question 4

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

Accepted Answer

Type I supernovae have very little hydro...

Question 5

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

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 6

A recurring nova could eventually explode as a Type I supernova.

Accepted Answer

A) True 
 B)False

Question 7

Whose work with SETI lead to the discovery of pulsars in 1967?

Accepted Answer

A)   Jocelyn Bell
B)   Sir Bernard Lovell
C)   Anthony Hewish
D)   Martin Schwarzschild
E)   Stephen Hawking

Question 8

Gamma-ray bursts seem to come primarily from neutron star binaries in the plane of our own Milky Way Galaxy.

Accepted Answer

A) True 
 B)False

Question 9

Supernova remnants differ from star forming regions because, although there is ionized hydrogen 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 10

Newly formed neutron stars have weak magnetic fields which strengthen over time, due to the conservation of angular momentum.

Accepted Answer

A) True 
 B)False

Question 11

Under what circumstances will a nova occur?

Accepted Answer

When a white dwarf pulls mass off its co...

Question 12

A hypernova creates

Accepted Answer

A)   a black hole.
B)   a pulsar.
C)   a neutron star.
D)   short-duration gamma-ray bursts.
E)   Both B and C are correct.

Question 13

Why is the post-Main Sequence structure of a high mass star sometimes described by an "onion-layer" model? Explain.

Accepted Answer

Late in the evolution of massive stars, ...

Question 14

What would happen if mass is added to a 1.4 solar mass white dwarf?

Accepted Answer

A)   The star would explode as a nova.
B)   The star's radius would increase.
C)   The star would immediately collapse into a black hole.
D)   The star would erupt as a carbon detonation (type I)  supernova.
E)   The core would collapse as a type II supernova.

Question 15

The central star of the Crab Nebula has now collapsed into a ________, whose energy keeps this famous nebula visible even in binoculars.

Accepted Answer

The answer of The central star of the Crab Nebula...

Question 16

In a nova, there is a white dwarf, an evolving companion star, and a(n) ________ surrounding the white dwarf's equator.

Accepted Answer

The answer of In a nova, there is a white...

Question 17

If successive generations of stars return material back to the interstellar medium which is enriched in heavier elements, then we expect that old stars are ________ compared to younger stars.

Accepted Answer

The answer of If successive generations of stars return material...

Question 18

Type I supernovae result from ________ stars which have accreted sufficient additional mass via mass transfer from a close binary companion.

Accepted Answer

The answer of Type I supernovae result from ________ stars...

Question 19

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

Accepted Answer

Basically the greater the mass of the at...

Question 20

What is the reason a type-I supernova slows its dimming after about 2 months?

Accepted Answer

A)   The planetary nebula cooled enough to form a dust shell.
B)   Energy is released from the decay of radioactive cobalt 56 to iron 56.
C)   The supernova remnant suddenly becomes transparent.
D)   The burst of energy carried by neutrinos is finally observed.
E)   Energy from the supernova's shock wave is released as it hits interstellar matter.

Exam 11: Stellar Explosions

What compelling evidence links pulsars to neutron stars?

Correct AnswerverifiedShow Answer

In a nova, there is a white dwarf, an evolving companion star, and a(n) ________ surrounding the white dwarf's equator.

Correct AnswerverifiedShow Answer

Except for hydrogen and most of the helium, all the elements have been formed through stellar nucleosynthesis.

Correct AnswerverifiedShow Answer

Whose work with SETI lead to the discovery of pulsars in 1967?

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

What is the reason a type-I supernova slows its dimming after about 2 months?

Correct AnswerverifiedShow Answer

What would happen if mass is added to a 1.4 solar mass white dwarf?

Correct AnswerverifiedShow Answer

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

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

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

Correct AnswerverifiedShow Answer

Why is the post-Main Sequence structure of a high mass star sometimes described by an "onion-layer" model? Explain.

Correct AnswerverifiedLate in the evolution of massive stars, ...View AnswerShow Answer

The central star of the Crab Nebula has now collapsed into a ________, whose energy keeps this famous nebula visible even in binoculars.

Correct AnswerverifiedShow Answer

Type I supernovae result from ________ stars which have accreted sufficient additional mass via mass transfer from a close binary companion.

Correct AnswerverifiedShow Answer

Supernova remnants differ from star forming regions because, although there is ionized hydrogen in both, supernova remnants

Correct AnswerverifiedShow Answer

Newly formed neutron stars have weak magnetic fields which strengthen over time, due to the conservation of angular momentum.

Correct AnswerverifiedShow Answer

Like most pulsars, the Crab Nebula neutron star is known only by its radio pulses.

Correct AnswerverifiedShow Answer

Under what circumstances will a nova occur?

Correct AnswerverifiedWhen a white dwarf pulls mass off its co...View AnswerShow Answer

Gamma-ray bursts seem to come primarily from neutron star binaries in the plane of our own Milky Way Galaxy.

Correct AnswerverifiedShow Answer

A hypernova creates

Correct AnswerverifiedShow Answer

If successive generations of stars return material back to the interstellar medium which is enriched in heavier elements, then we expect that old stars are ________ compared to younger stars.

Correct AnswerverifiedShow Answer

A recurring nova could eventually explode as a Type I supernova.

Correct AnswerverifiedShow Answer

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Type I supernovae have very little hydro...
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Basically the greater the mass of the at...
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Late in the evolution of massive stars, ...
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When a white dwarf pulls mass off its co...
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