Question 1

Compare the amount of time a 20 solar mass star will stay on the main sequence to the lengthof time its iron core can exist.

Accepted Answer

A 20 solar mass star will stay...

Question 2

A carbon-detonation supernova starts out as a white dwarf in a close binary system.

Accepted Answer

A) True 
 B)False

Question 3

The Chandrasekhar Limit is:

Accepted Answer

A)  the upper mass limit for a white dwarf.
B)  the temperature at which hydrogen fusion starts.
C)  the temperature at which helium fusion starts.
D)  the point at which a planetary nebula forms.
E)  the lower mass limit for a Type II supernova.F) A) and D)
G) C) and E)

Question 4

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

Accepted Answer

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

Question 5

Why are neutrinos from a Type II supernova detected before photons?

Accepted Answer

A)  Neutrinos travel faster than photons.
B)  Neutrinos are easier to detect than photons.
C)  Neutrinos are produced in the explosion before photons.
D)  Neutrinos are emitted from the outer part of the star; photons come from the core.
E)  Neutrinos escape from the star quickly because they hardly interact with matter; photons aredelayed by interactions with matter.F) C) and D)
G) B) and E)

Question 6

As a star's evolution approaches the Type II supernova, we find:

Accepted Answer

A)  the heavier the element, the less time it takes to make it.
B)  the heavier the element, the higher the temperature to fuse it.
C)  helium to carbon fusion takes at least 100 million K to start.
D)  photodisintegration of iron nuclei begins at 10 billion K to ignite the supernova.
E)  All of the above are correct.F) B) and D)
G) B) and C)

Question 7

Stellar nucleosynthesis is responsible for the existence of all elements except hydrogen.

Accepted Answer

A) True 
 B)False

Question 8

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.F) A) and D)
G) A) and C)

Question 9

What is the CNO cycle and how is it different from hydrogen fusion via the proton-protonchain?

Accepted Answer

The CNO cycle is a kind of hydrogen fusi...

Question 10

What do X-ray observations tell us about conditions around a potential nova?

Accepted Answer

The mass transfer causes an accretion di...

Question 11

The total energy emitted by the brightest nova explosions is about:

Accepted Answer

A)  1,000 Suns.
B)  50,000 Suns.
C)  a million Suns.
D)  a billion Suns.
E)  a trillion Suns.F) None of the above
G) B) and C)

Question 12

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

Accepted Answer

A) True 
 B)False

Question 13

Most of the energy released during a supernova is emitted as neutrinos.

Accepted Answer

A) True 
 B)False

Question 14

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.F) A) and E)
G) A) and C)

Question 15

What is the only element in your body that was formed during the Big Bang, and not in coresof stars? Explain how you know this.

Accepted Answer

Hydrogen was formed during the...

Question 16

An iron core will collapse in approximately one ________ in a Type II supernova event.

Accepted Answer

The answer of An iron core will collapse in approximately...

Question 17

The Crab Nebula is a bright, long-lasting supernova remnant that was made by a ________supernova.

Accepted Answer

The answer of The Crab Nebula is a bright, long-lasting...

Question 18

Why does conversion of its core to iron have to mark the end of a star's life? Which stars canend up with iron cores?

Accepted Answer

Stars with a total mass of 8 solar masse...

Question 19

An iron core cannot support a star because:

Accepted Answer

A)  iron is the heaviest element, and sinks upon differentiation.
B)  iron has poor nuclear binding energy.
C)  iron cannot fuse with other nuclei to produce energy.
D)  iron supplies too much pressure.
E)  iron is in the form of a gas, not a solid, in the center of a star.F) None of the above
G) B) and E)

Question 20

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.F) A) and E)
G) C) and D)

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

Compare the amount of time a 20 solar mass star will stay on the main sequence to the lengthof time its iron core can exist.

Correct AnswerverifiedA 20 solar mass star will stay...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

The total energy emitted by the brightest nova explosions is about:

Correct AnswerverifiedShow Answer

An iron core will collapse in approximately one ________ in a Type II supernova event.

Correct AnswerverifiedShow Answer

Most of the energy released during a supernova is emitted as neutrinos.

Correct AnswerverifiedShow Answer

What is the only element in your body that was formed during the Big Bang, and not in coresof stars? Explain how you know this.

Correct AnswerverifiedHydrogen was formed during the...View AnswerShow Answer

As a star's evolution approaches the Type II supernova, we find:

Correct AnswerverifiedShow Answer

Why does conversion of its core to iron have to mark the end of a star's life? Which stars canend up with iron cores?

Correct AnswerverifiedStars with a total mass of 8 solar masse...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

The Crab Nebula is a bright, long-lasting supernova remnant that was made by a ________supernova.

Correct AnswerverifiedShow Answer

The Chandrasekhar Limit is:

Correct AnswerverifiedShow Answer

An iron core cannot support a star because:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Stellar nucleosynthesis is responsible for the existence of all elements except hydrogen.

Correct AnswerverifiedShow Answer

What do X-ray observations tell us about conditions around a potential nova?

Correct AnswerverifiedThe mass transfer causes an accretion di...View AnswerShow Answer

What is the CNO cycle and how is it different from hydrogen fusion via the proton-protonchain?

Correct AnswerverifiedThe CNO cycle is a kind of hydrogen fusi...View AnswerShow Answer

Why are neutrinos from a Type II supernova detected before photons?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A carbon-detonation supernova starts out as a white dwarf in a close binary system.

Correct AnswerverifiedShow Answer

Correct Answer
verified
A 20 solar mass star will stay...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Hydrogen was formed during the...
View Answer

Correct Answer
verified

Correct Answer
verified
Stars with a total mass of 8 solar masse...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The mass transfer causes an accretion di...
View Answer

Correct Answer
verified
The CNO cycle is a kind of hydrogen fusi...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified