Question 1

What observational evidence proved that gamma ray bursts do not come from objects in our galaxy?

Accepted Answer

Gamma ray bursts are observed in every d

Question 2

Millisecond pulsars _____.

Accepted Answer

A)  are created in supernova explosions of the most massive stars 
B)  result from the collision of two neutron stars 
C)  represent the youngest pulsars detected 
D)  result from long-term mass transfer from a companion star 
E)  are a theoretical prediction that has not been observed 
A)  are created in supernova explosions of the most massive stars 
B)  result from the collision of two neutron stars 
C)  represent the youngest pulsars detected 
D)  result from long-term mass transfer from a companion star 
E)  are a theoretical prediction that has not been observed

Question 3

A neutron star, which generates gamma-ray bursts due to "starquakes" on its surface, is called a(n) _______________.

Accepted Answer

The answer of A neutron star, which generates gamma-ray bursts...

Question 4

X-ray bursters are caused by black holes.

Accepted Answer

A) True 
 B)False

Question 5

Neutron stars are supported by _____.

Accepted Answer

A)  neutron gas pressure 
B)  hydrogen gas pressure 
C)  electron degeneracy pressure 
D)  neutron degeneracy pressure 
E)  hydrogen degeneracy pressure 
A)  neutron gas pressure 
B)  hydrogen gas pressure 
C)  electron degeneracy pressure 
D)  neutron degeneracy pressure 
E)  hydrogen degeneracy pressure

Question 6

Pulsars can be created by neutron stars or black holes.

Accepted Answer

A) True 
 B)False

Question 7

If the Sun was replaced by a black hole of equal mass, Earth would _____.

Accepted Answer

A)  fall into the black hole on a virtually straight path 
B)  spiral in to the black hole over several months 
C)  spiral in to the black hole over the course of several decades 
D)  continue in its normal orbit 
E)  spiral away from the black hole, pushed by gravitational waves 
A)  fall into the black hole on a virtually straight path 
B)  spiral in to the black hole over several months 
C)  spiral in to the black hole over the course of several decades 
D)  continue in its normal orbit 
E)  spiral away from the black hole, pushed by gravitational waves

Question 8

Supernova remnants _____.

Accepted Answer

A)  always contain pulsars, because pulsars supply the ionizing radiation 
B)  often last longer than a pulsar does, so the central pulsar may no longer be visible 
C)  rarely contain pulsars, because pulsar radiation disrupts the remnant 
D)  may not contain a pulsar, if the supernova explosion kicked the pulsar away at high speed 
E)  never contain pulsars 
A)  always contain pulsars, because pulsars supply the ionizing radiation 
B)  often last longer than a pulsar does, so the central pulsar may no longer be visible 
C)  rarely contain pulsars, because pulsar radiation disrupts the remnant 
D)  may not contain a pulsar, if the supernova explosion kicked the pulsar away at high speed 
E)  never contain pulsars

Question 9

Which statement best describes a neutron star's formation as a supernova explodes and the core begins to collapse inward?

Accepted Answer

A)  neutrinos and antineutrinos combine into neutrons 
B)  electrons and protons combine into neutrons and neutrinos 
C)  Electrons and protons combine into neutrons and neutrinos 
D)  electrons and positrons combine into neutrons and neutrinos 
E)  protons and antiprotons combine into neutrons and neutrinos 
A)  neutrinos and antineutrinos combine into neutrons 
B)  electrons and protons combine into neutrons and neutrinos 
C)  Electrons and protons combine into neutrons and neutrinos 
D)  electrons and positrons combine into neutrons and neutrinos 
E)  protons and antiprotons combine into neutrons and neutrinos

Question 10

A neutron star is created when a(n) ___.

Accepted Answer

A)  collapsing stellar core exceeds the Schwarzschild limit 
B)  stellar core ignites iron fusion 
C)  collapsing stellar core exceeds the Chandrasekhar limit 
D)  stellar core exceeds the Roche limit 
E)  collapsing stellar core exceeds the Hawking limit 
A)  collapsing stellar core exceeds the Schwarzschild limit 
B)  stellar core ignites iron fusion 
C)  collapsing stellar core exceeds the Chandrasekhar limit 
D)  stellar core exceeds the Roche limit 
E)  collapsing stellar core exceeds the Hawking limit

Question 11

An X-ray burster occurs in a pulsar when ____.

Accepted Answer

A)  accreted helium suddenly fuses in a nova-like explosion 
B)  the Chandrasekhar limit is exceeded and the object collapses 
C)  carbon deflagration destroys the object 
D)  it merges with a binary companion 
E)  hydrogen fusion ignites in an accretion disk around it 
A)  accreted helium suddenly fuses in a nova-like explosion 
B)  the Chandrasekhar limit is exceeded and the object collapses 
C)  carbon deflagration destroys the object 
D)  it merges with a binary companion 
E)  hydrogen fusion ignites in an accretion disk around it

Question 12

Pulsars were discovered because they _____.

Accepted Answer

A)  provide the energy to ionize supernova remnants 
B)  radiate gravitational waves 
C)  absorb matter from a binary companion through an accretion disk 
D)  emit short, regular bursts of radiation 
E)  undergo nova eruptions on a regular period of a few years 
A)  provide the energy to ionize supernova remnants 
B)  radiate gravitational waves 
C)  absorb matter from a binary companion through an accretion disk 
D)  emit short, regular bursts of radiation 
E)  undergo nova eruptions on a regular period of a few years

Question 13

The first confirmed black hole, Cygnus X-1, was regarded as proof that black holes exist because it

Accepted Answer

A)  is a compact object in a binary system 
B)  emits X-rays from a hot accretion disk 
C)  is accreting matter from a main-sequence companion 
D)  has a period of 5.6 days 
E)  has a mass of ten solar masses 
A)  is a compact object in a binary system 
B)  emits X-rays from a hot accretion disk 
C)  is accreting matter from a main-sequence companion 
D)  has a period of 5.6 days 
E)  has a mass of ten solar masses

Question 14

Neutron stars radiate most of their energy in the ____ wavelength band(s).

Accepted Answer

A)  radio and infrared 
B)  radio and X-ray 
C)  visible 
D)  visible and gamma-ray 
E)  X-ray and gamma-ray 
A)  radio and infrared 
B)  radio and X-ray 
C)  visible 
D)  visible and gamma-ray 
E)  X-ray and gamma-ray

Question 15

A neutron star must have a mass greater than 2.4 solar masses.

Accepted Answer

A) True 
 B)False

Question 16

What is a "hypernova," and how do they produce observable gamma ray bursts?

Accepted Answer

A star more massive than 20 solar masses

Question 17

Gas falling into a black hole:

Accepted Answer

A)  is heated to millions of degrees through the loss of gravitational energy 
B)  is cooled to near absolute zero through the loss of gravitational energy 
C)  releases energy, all of which is absorbed by the black hole 
D)  never reaches the black hole due to the effect of time dilation 
E)  orbits the black hole but cannot cross the event horizon 
A)  is heated to millions of degrees through the loss of gravitational energy 
B)  is cooled to near absolute zero through the loss of gravitational energy 
C)  releases energy, all of which is absorbed by the black hole 
D)  never reaches the black hole due to the effect of time dilation 
E)  orbits the black hole but cannot cross the event horizon

Question 18

Why are black holes called "black"?

Accepted Answer

The escape velocity of a celestial objec

Question 19

In a binary system containing two neutron stars, the objects will ____.

Accepted Answer

A)  radiate orbital energy away as gravitational radiation and move farther apart 
B)  radiate orbital energy away as gravitational radiation and move closer together 
C)  exchange mass until their orbital periods become equal 
D)  exchange mass until they are in synchronous rotation 
E)  exchange angular momentum, lengthening the period of the pulsar 
A)  radiate orbital energy away as gravitational radiation and move farther apart 
B)  radiate orbital energy away as gravitational radiation and move closer together 
C)  exchange mass until their orbital periods become equal 
D)  exchange mass until they are in synchronous rotation 
E)  exchange angular momentum, lengthening the period of the pulsar

Question 20

Extremely old pulsars that have experienced large amounts of mass transfer may become _______________ pulsars.

Accepted Answer

millisecon

Exam 14: Neutron Stars and Black Holes

What observational evidence proved that gamma ray bursts do not come from objects in our galaxy?

Millisecond pulsars _____.

A neutron star, which generates gamma-ray bursts due to "starquakes" on its surface, is called a(n) _______________.

X-ray bursters are caused by black holes.

Neutron stars are supported by _____.

Pulsars can be created by neutron stars or black holes.

If the Sun was replaced by a black hole of equal mass, Earth would _____.

Supernova remnants _____.

Which statement best describes a neutron star's formation as a supernova explodes and the core begins to collapse inward?

A neutron star is created when a(n) ___.

An X-ray burster occurs in a pulsar when ____.

Pulsars were discovered because they _____.

The first confirmed black hole, Cygnus X-1, was regarded as proof that black holes exist because it

Neutron stars radiate most of their energy in the ____ wavelength band(s).

A neutron star must have a mass greater than 2.4 solar masses.

What is a "hypernova," and how do they produce observable gamma ray bursts?

Gas falling into a black hole:

Why are black holes called "black"?

In a binary system containing two neutron stars, the objects will ____.

Extremely old pulsars that have experienced large amounts of mass transfer may become _______________ pulsars.

Here and Now

A Users Guide to the Sky

Moon Phases and Eclipses

Origins of Modern Astronomy

Gravity

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Interstellar Medium

Formation and Structure of Stars

Stellar Evolution

Deaths of Stars

The Milky Way Galaxy

Galaxies

Supermassive Black Holes and Active Galaxies

Modern Cosmology

Origin of the Solar System and Extrasolar Planets

Earth the Active Planet

The Moon and Mercury

Venus and Mars

Jupiter and Saturn

Uranus Neptune Pluto and the Kuiper Belt

Meteorites Asteroids and Comets

Astrobiology

Filters