Question 1

A compact object emitting very regularly spaced bursts of radio energy is known as a(n) _______________.

Accepted Answer

pulsar

Question 2

The _______________ model explains pulsars using beams of radiation that sweep around the sky.

Accepted Answer

lighthouse,light house

Question 3

Jets from compact objects are explained by the effect of _____.

Accepted Answer

A)  magnetic fields 
B)  gravitational waves 
C)  angular momentum 
D)  mass transfer 
E)  pulsar winds 
A)  magnetic fields 
B)  gravitational waves 
C)  angular momentum 
D)  mass transfer 
E)  pulsar winds A

Question 4

Imagine an astronaut falling into a black hole. Describe the effects that the astronaut would experience firsthand, and the changes that an external observer would see.

Accepted Answer

The astronaut would notice that initiall

Question 5

Why do some supernovae form neutron star remnants instead of white dwarfs?

Accepted Answer

The Chandrasekhar limit specifies that t

Question 6

A compact object with a mass of 4 solar masses must be a black hole.

Accepted Answer

A) True 
 B)False

Question 7

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 8

Pulsar planets are _____.

Accepted Answer

A)  huge gas planets that could be classified as brown dwarfs 
B)  asteroids captured from interstellar space 
C)  observed, but not fully understood 
D)  predicted, but have not been observed 
E)  Earth-like, and may harbor life 
A)  huge gas planets that could be classified as brown dwarfs 
B)  asteroids captured from interstellar space 
C)  observed, but not fully understood 
D)  predicted, but have not been observed 
E)  Earth-like, and may harbor life

Question 9

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 10

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 11

Why are millisecond pulsars often found in binary systems with small red- or brown-dwarf companions?

Accepted Answer

A normal pulsar has a period of a few te

Question 12

A hypernova is a violent event caused by _____.

Accepted Answer

A)  the merger of two neutron stars 
B)  the collapse of a rapidly rotating massive star 
C)  the fusion of a layer of degenerate helium deposited on the surface of a neutron star 
D)  carbon deflagration in a neutron star 
E)  the crossing of jets from two compact objects 
A)  the merger of two neutron stars 
B)  the collapse of a rapidly rotating massive star 
C)  the fusion of a layer of degenerate helium deposited on the surface of a neutron star 
D)  carbon deflagration in a neutron star 
E)  the crossing of jets from two compact objects

Question 13

The jets emitted by compact objects are made of _____.

Accepted Answer

A)  X-rays 
B)  atomic nuclei 
C)  neutrons 
D)  neutrinos 
E)  positrons 
A)  X-rays 
B)  atomic nuclei 
C)  neutrons 
D)  neutrinos 
E)  positrons

Question 14

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 15

Pulsars can be created by neutron stars or black holes.

Accepted Answer

A) True 
 B)False

Question 16

An astronomer examining a compact object could conclude that it was a black hole if it _____.

Accepted Answer

A)  emits regular pulses of radiation 
B)  has a defined event horizon that emits X-rays 
C)  has an accretion disk 
D)  has a mass greater than 1.4 solar masses 
E)  has a mass greater than 3 solar masses 
A)  emits regular pulses of radiation 
B)  has a defined event horizon that emits X-rays 
C)  has an accretion disk 
D)  has a mass greater than 1.4 solar masses 
E)  has a mass greater than 3 solar masses

Question 17

Why are black holes called "black"?

Accepted Answer

The escape velocity of a celestial objec

Question 18

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 19

Explain the "Lighthouse Model" of pulsars.

Accepted Answer

A neutron star has a very strong magneti

Question 20

Schwarzschild showed how the _______________ of the event horizon depends only on the mass of the black hole.

Accepted Answer

The answer of Schwarzschild showed how the _______________ of the...

Exam 14: Neutron Stars and Black Holes

A compact object emitting very regularly spaced bursts of radio energy is known as a(n) _______________.

The _______________ model explains pulsars using beams of radiation that sweep around the sky.

Jets from compact objects are explained by the effect of _____.

Imagine an astronaut falling into a black hole. Describe the effects that the astronaut would experience firsthand, and the changes that an external observer would see.

Why do some supernovae form neutron star remnants instead of white dwarfs?

A compact object with a mass of 4 solar masses must be a black hole.

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

Pulsar planets are _____.

Neutron stars are supported by _____.

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

Why are millisecond pulsars often found in binary systems with small red- or brown-dwarf companions?

A hypernova is a violent event caused by _____.

The jets emitted by compact objects are made of _____.

Gas falling into a black hole:

Pulsars can be created by neutron stars or black holes.

An astronomer examining a compact object could conclude that it was a black hole if it _____.

Why are black holes called "black"?

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

Explain the "Lighthouse Model" of pulsars.

Schwarzschild showed how the _______________ of the event horizon depends only on the mass of the black hole.

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Origins of Modern Astronomy

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