AST 105 EXAM 2 CH 14 QUESTIONS WITH ALL
CORRECT & VERIFIED ANSWERS
3 Correct answer-At peak brightness, the white dwarf supernova is approximately __________
times as luminous as the massive star supernova at its peak brightness.
1% Correct answer-For the white dwarf supernova, the luminosity 175 days after it reaches peak
brightness is about __________ of the luminosity at peak brightness.
30 days Correct answer-Approximately how many days does it take for a white dwarf supernova to
decline to 10% of its peak brightness?
100 days Correct answer-Approximately how many days does it take for a massive star supernova
to decline to 10% of its peak brightness?
300 days Correct answer-Approximately how many days does it take for a massive star supernova
to decline to 1% of its peak brightness?
subatomic particles are packed as tightly as the laws of quantum mechanics allow Correct answer-
Degenearcy pressure arises when ________.
the merger of two black holes Correct answer-Gravitational waves were first detected directly in
2015. According to models, the source of these gravitational waves was __________.
electron degeneracy pressure Correct answer-A white dwarf can remain stable in size because of
________________________________
singularity Correct answer-The ___________________ is the place to which all of a black hole's
mass is in principle located within the black hole.
accretion disk Correct answer-A(n) ___________________ can form around a white dwarf, neutron
star, or black hole in a binary system
event horizon Correct answer-The ___________________ marks the boundary between the inside
and outside of a black hole.
neutron degeneracy pressure Correct answer-A neutron star can remain stable in size because of
_____________________________
nova Correct answer-A(n) ____________ occurs when fusion ignites on the surface of a white
dwarf.
pulsar Correct answer-A(n) ___________ is rapidly rotating neutron star.
what most stars become when they die Correct answer-A white dwarf is _________.
as massive as the Sun but only about as large in size as Earth Correct answer-A typical white dwarf
is _________.
about 5 pounds Correct answer-If you had something the size of a sugar cube that was made of
white dwarf matter, it would weigh _________.
, about 1.4 times the mass of our Sun Correct answer-The maximum mass of a white dwarf is
_________.
A disk of hot gas swirling rapidly around a white dwarf, neutron star, or black hole Correct answer-
What is an accretion disk?
An explosion on the surface of a white dwarf in a close binary system Correct answer-According to
our modern understanding, what is a nova?
The white dwarf will explode completely as a white dwarf supernova. Correct answer-Suppose that
a white dwarf gains enough mass to reach the 1.4-solar-mass limit; what will happen next?
the remains of a star that died in a massive star supernova (if no black hole was created) Correct
answer-A neutron star is _________.
a small asteroid (10 km in diameter) Correct answer-A typical neutron star is more massive than
our Sun and about the size (radius) of _________.
about as much as a large mountain Correct answer-If you had something the size of a sugar cube
that was made of neutron star matter, it would weigh _________.
Electron degeneracy pressure is the main source of pressure in white dwarfs, while neutron
degeneracy pressure is the main source of pressure in neutron stars. Correct answer-Which of the
following statements about electron degeneracy pressure and neutron degeneracy pressure is true?
rapidly rotating neutron stars Correct answer-Pulsars are thought to be _________.
Both involve explosions on the surface of stellar corpse. Correct answer-How is an X-ray burst (in
an X-ray binary system) similar to a nova?
An object with gravity so strong that not even light can escape Correct answer-What is the basic
definition of a black hole?
3 solar masses Correct answer-Based on current understanding, the minimum mass of a black hole
that forms during a massive star supernova is roughly _________.
It is the point beyond which neither light nor anything else can escape. Correct answer-What do
we mean by the event horizon of a black hole?
Nothing. Earth's orbit would remain the same. Correct answer-Imagine that our Sun were
magically and suddenly replaced by a black hole of the same mass (1 solar mass). What would
happen to Earth in its orbit?
It is the center of the black hole, a place of infinite density where the known laws of physics cannot
describe the conditions. Correct answer-What do we mean by the singularity of a black hole?
It emits X-rays characteristic of an accretion disk, but the unseen star in the system is too massive to
be a neutron star Correct answer-What makes us think that the star system Cygnus X-1 contains a
black hole?
CORRECT & VERIFIED ANSWERS
3 Correct answer-At peak brightness, the white dwarf supernova is approximately __________
times as luminous as the massive star supernova at its peak brightness.
1% Correct answer-For the white dwarf supernova, the luminosity 175 days after it reaches peak
brightness is about __________ of the luminosity at peak brightness.
30 days Correct answer-Approximately how many days does it take for a white dwarf supernova to
decline to 10% of its peak brightness?
100 days Correct answer-Approximately how many days does it take for a massive star supernova
to decline to 10% of its peak brightness?
300 days Correct answer-Approximately how many days does it take for a massive star supernova
to decline to 1% of its peak brightness?
subatomic particles are packed as tightly as the laws of quantum mechanics allow Correct answer-
Degenearcy pressure arises when ________.
the merger of two black holes Correct answer-Gravitational waves were first detected directly in
2015. According to models, the source of these gravitational waves was __________.
electron degeneracy pressure Correct answer-A white dwarf can remain stable in size because of
________________________________
singularity Correct answer-The ___________________ is the place to which all of a black hole's
mass is in principle located within the black hole.
accretion disk Correct answer-A(n) ___________________ can form around a white dwarf, neutron
star, or black hole in a binary system
event horizon Correct answer-The ___________________ marks the boundary between the inside
and outside of a black hole.
neutron degeneracy pressure Correct answer-A neutron star can remain stable in size because of
_____________________________
nova Correct answer-A(n) ____________ occurs when fusion ignites on the surface of a white
dwarf.
pulsar Correct answer-A(n) ___________ is rapidly rotating neutron star.
what most stars become when they die Correct answer-A white dwarf is _________.
as massive as the Sun but only about as large in size as Earth Correct answer-A typical white dwarf
is _________.
about 5 pounds Correct answer-If you had something the size of a sugar cube that was made of
white dwarf matter, it would weigh _________.
, about 1.4 times the mass of our Sun Correct answer-The maximum mass of a white dwarf is
_________.
A disk of hot gas swirling rapidly around a white dwarf, neutron star, or black hole Correct answer-
What is an accretion disk?
An explosion on the surface of a white dwarf in a close binary system Correct answer-According to
our modern understanding, what is a nova?
The white dwarf will explode completely as a white dwarf supernova. Correct answer-Suppose that
a white dwarf gains enough mass to reach the 1.4-solar-mass limit; what will happen next?
the remains of a star that died in a massive star supernova (if no black hole was created) Correct
answer-A neutron star is _________.
a small asteroid (10 km in diameter) Correct answer-A typical neutron star is more massive than
our Sun and about the size (radius) of _________.
about as much as a large mountain Correct answer-If you had something the size of a sugar cube
that was made of neutron star matter, it would weigh _________.
Electron degeneracy pressure is the main source of pressure in white dwarfs, while neutron
degeneracy pressure is the main source of pressure in neutron stars. Correct answer-Which of the
following statements about electron degeneracy pressure and neutron degeneracy pressure is true?
rapidly rotating neutron stars Correct answer-Pulsars are thought to be _________.
Both involve explosions on the surface of stellar corpse. Correct answer-How is an X-ray burst (in
an X-ray binary system) similar to a nova?
An object with gravity so strong that not even light can escape Correct answer-What is the basic
definition of a black hole?
3 solar masses Correct answer-Based on current understanding, the minimum mass of a black hole
that forms during a massive star supernova is roughly _________.
It is the point beyond which neither light nor anything else can escape. Correct answer-What do
we mean by the event horizon of a black hole?
Nothing. Earth's orbit would remain the same. Correct answer-Imagine that our Sun were
magically and suddenly replaced by a black hole of the same mass (1 solar mass). What would
happen to Earth in its orbit?
It is the center of the black hole, a place of infinite density where the known laws of physics cannot
describe the conditions. Correct answer-What do we mean by the singularity of a black hole?
It emits X-rays characteristic of an accretion disk, but the unseen star in the system is too massive to
be a neutron star Correct answer-What makes us think that the star system Cygnus X-1 contains a
black hole?
