Question 1

If the accretion disk around a black hole emits X-rays outside the event horizon,the X-rays can escape the gravitational well.

Accepted Answer

A) True 
 B)False

Question 2

What is the defining characteristic of stars within a cluster that are at the turnoff point?

Accepted Answer

A) They are just leaving the main sequence. 
B) They are just becoming white dwarfs. 
C) They are just entering the main sequence. 
D) They are about to explode in supernovae. 
A) They are just leaving the main sequence. 
B) They are just becoming white dwarfs. 
C) They are just entering the main sequence. 
D) They are about to explode in supernovae.

Question 3

The helium flash is the cause of some supernovae.

Accepted Answer

A) True 
 B)False

Question 4

As a white dwarf cools,why does its radius NOT change?

Accepted Answer

A) because pressure due to nuclear reactions in a shell just below the surface keeps it from collapsing 
B) because pressure does not depend on temperature for a white dwarf, since the electrons are degenerate 
C) because pressure does not depend on temperature, since the star has exhausted all its nuclear fuels 
D) because material accreting onto it from a companion maintains a constant radius 
A) because pressure due to nuclear reactions in a shell just below the surface keeps it from collapsing 
B) because pressure does not depend on temperature for a white dwarf, since the electrons are degenerate 
C) because pressure does not depend on temperature, since the star has exhausted all its nuclear fuels 
D) because material accreting onto it from a companion maintains a constant radius

Question 5

Why does a helium flash occur under some circumstances and not under other circumstances when helium fusion begins?

Accepted Answer

The answer of Why does a helium flash occur under...

Question 6

What are hypernovae?

Accepted Answer

A) supernovae that occur when two red dwarfs collide 
B) supernovae that occur when 10 solar mass stars explode 
C) supernovae that occur when stars more massive than 25 solar masses explode 
D) supernovae that occur when two black holes collide 
A) supernovae that occur when two red dwarfs collide 
B) supernovae that occur when 10 solar mass stars explode 
C) supernovae that occur when stars more massive than 25 solar masses explode 
D) supernovae that occur when two black holes collide

Question 7

What is the term that describes the slowing of clocks in strongly curved space-time?

Accepted Answer

A) gravitational radiation 
B) time dilation 
C) gravitational red shift 
D) hyperspace drag 
A) gravitational radiation 
B) time dilation 
C) gravitational red shift 
D) hyperspace drag

Question 8

No known white dwarf has a mass greater than the Chandrasekhar-Landau limit.

Accepted Answer

A) True 
 B)False

Question 9

What has greater density than a white dwarf?

Accepted Answer

A) a neutron star 
B) a red dwarf 
C) a brown dwarf 
D) a red giant 
A) a neutron star 
B) a red dwarf 
C) a brown dwarf 
D) a red giant

Question 10

What property is the same for all stars in a star cluster?

Accepted Answer

A) age 
B) mass 
C) luminosity 
D) radius 
A) age 
B) mass 
C) luminosity 
D) radius

Question 11

A(n)____________________ is formed by the expulsion of the outer layers of a moderate mass star that has a degenerate carbon and oxygen core.

Accepted Answer

The answer of A(n)____________________ is formed by the expulsion of...

Question 12

Stars swell into giants when hydrogen is exhausted in their centres.

Accepted Answer

A) True 
 B)False

Question 13

What evidence do we have that pulsars are neutron stars?

Accepted Answer

The answer of What evidence do we have that pulsars...

Question 14

A(n)____________________ is a rapidly spinning neutron star that accelerates charged particles near the poles of its magnetic field.

Accepted Answer

The answer of A(n)____________________ is a rapidly spinning neutron star...

Question 15

-Refer to the H-R diagram.How would the H-R diagram of an older star cluster look different?

Accepted Answer

A) The points would shift to the right, because all of the stars would have lower temperatures. 
B) The lower main sequence would look the same, but the turnoff would be at spectral type K or M. 
C) The points would shift down, because all of the stars would have lower luminosities. 
D) The lower main sequence would look the same, but the turnoff would be at spectral type F or A. 
A) The points would shift to the right, because all of the stars would have lower temperatures. 
B) The lower main sequence would look the same, but the turnoff would be at spectral type K or M. 
C) The points would shift down, because all of the stars would have lower luminosities. 
D) The lower main sequence would look the same, but the turnoff would be at spectral type F or A.

Question 16

What is a white dwarf composed of?

Accepted Answer

A) hydrogen nuclei and degenerate electrons 
B) helium nuclei and normal electrons 
C) carbon and oxygen nuclei and degenerate electrons 
D) degenerate iron nuclei 
A) hydrogen nuclei and degenerate electrons 
B) helium nuclei and normal electrons 
C) carbon and oxygen nuclei and degenerate electrons 
D) degenerate iron nuclei

Question 17

In the year 10⁵4 CE,Chinese astronomers observed the appearance of a new star.What occupies that location now?

Accepted Answer

A) a molecular cloud 
B) a planetary nebula with a white dwarf in the centre 
C) a supernova remnant with a pulsar in the centre 
D) nothing 
A) a molecular cloud 
B) a planetary nebula with a white dwarf in the centre 
C) a supernova remnant with a pulsar in the centre 
D) nothing

Question 18

Which nuclear fuels does a one solar mass star use over the course of its entire lifespan?

Accepted Answer

A) hydrogen 
B) hydrogen and helium 
C) hydrogen, helium, and carbon 
D) hydrogen, helium, carbon, and oxygen 
A) hydrogen 
B) hydrogen and helium 
C) hydrogen, helium, and carbon 
D) hydrogen, helium, carbon, and oxygen

Question 19

What does a planetary nebula do?

Accepted Answer

A) produces an absorption spectrum 
B) produces an emission spectrum 
C) contracts to form planets 
D) contracts to form a star 
A) produces an absorption spectrum 
B) produces an emission spectrum 
C) contracts to form planets 
D) contracts to form a star

Question 20

Which of the following are neutron stars that have magnetic fields 100 times stronger than the average neutron star?

Accepted Answer

A) hypernovae 
B) collapsars 
C) pulsars 
D) magnetars 
A) hypernovae 
B) collapsars 
C) pulsars 
D) magnetars

If the accretion disk around a black hole emits X-rays outside the event horizon,the X-rays can escape the gravitational well.

What is the defining characteristic of stars within a cluster that are at the turnoff point?

The helium flash is the cause of some supernovae.

As a white dwarf cools,why does its radius NOT change?

Why does a helium flash occur under some circumstances and not under other circumstances when helium fusion begins?

What are hypernovae?

What is the term that describes the slowing of clocks in strongly curved space-time?

No known white dwarf has a mass greater than the Chandrasekhar-Landau limit.

What has greater density than a white dwarf?

What property is the same for all stars in a star cluster?

A(n)____________________ is formed by the expulsion of the outer layers of a moderate mass star that has a degenerate carbon and oxygen core.

Stars swell into giants when hydrogen is exhausted in their centres.

What evidence do we have that pulsars are neutron stars?

A(n)____________________ is a rapidly spinning neutron star that accelerates charged particles near the poles of its magnetic field.

-Refer to the H-R diagram.How would the H-R diagram of an older star cluster look different?

What is a white dwarf composed of?

In the year 10⁵4 CE,Chinese astronomers observed the appearance of a new star.What occupies that location now?

Which nuclear fuels does a one solar mass star use over the course of its entire lifespan?

What does a planetary nebula do?

Which of the following are neutron stars that have magnetic fields 100 times stronger than the average neutron star?

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Structure and Formation of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

Filters

Exam 8: The Deaths of Stars

If the accretion disk around a black hole emits X-rays outside the event horizon,the X-rays can escape the gravitational well.

What is the defining characteristic of stars within a cluster that are at the turnoff point?

The helium flash is the cause of some supernovae.

As a white dwarf cools,why does its radius NOT change?

Why does a helium flash occur under some circumstances and not under other circumstances when helium fusion begins?

What are hypernovae?

What is the term that describes the slowing of clocks in strongly curved space-time?

No known white dwarf has a mass greater than the Chandrasekhar-Landau limit.

What has greater density than a white dwarf?

What property is the same for all stars in a star cluster?

A(n)____________________ is formed by the expulsion of the outer layers of a moderate mass star that has a degenerate carbon and oxygen core.

Stars swell into giants when hydrogen is exhausted in their centres.

What evidence do we have that pulsars are neutron stars?

A(n)____________________ is a rapidly spinning neutron star that accelerates charged particles near the poles of its magnetic field.

-Refer to the H-R diagram.How would the H-R diagram of an older star cluster look different?

What is a white dwarf composed of?

In the year 10⁵4 CE,Chinese astronomers observed the appearance of a new star.What occupies that location now?

Which nuclear fuels does a one solar mass star use over the course of its entire lifespan?

What does a planetary nebula do?

Which of the following are neutron stars that have magnetic fields 100 times stronger than the average neutron star?

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Structure and Formation of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

Filters