Question 1

Evidence for the conclusion that the longer-living gamma-ray bursters are very distant comes from the:

Accepted Answer

A)  extreme redshift of emission lines in the visible spectrum detected after a gamma-ray burst. 
B)  delay in the arrival of the visible pulse behind the gamma-ray pulse, caused by the passage of the light through optically thick intergalactic material. 
C)  spread in arrival times of different gamma-ray photon energies, indicating a long passage through intergalactic gas. 
D)  presence of absorption lines from intergalactic gas clouds in the spectrum of remnant visible light following the gamma-ray burst. 
A)  extreme redshift of emission lines in the visible spectrum detected after a gamma-ray burst. 
B)  delay in the arrival of the visible pulse behind the gamma-ray pulse, caused by the passage of the light through optically thick intergalactic material. 
C)  spread in arrival times of different gamma-ray photon energies, indicating a long passage through intergalactic gas. 
D)  presence of absorption lines from intergalactic gas clouds in the spectrum of remnant visible light following the gamma-ray burst.

Question 2

What is the last nuclear fusion stage in the life of a low-mass star like the Sun?

Accepted Answer

A)  fusion of silicon nuclei to form iron 
B)  fusion of oxygen nuclei to form sulfur 
C)  fusion of helium nuclei to form carbon and oxygen 
D)  fusion of hydrogen nuclei to form helium 
A)  fusion of silicon nuclei to form iron 
B)  fusion of oxygen nuclei to form sulfur 
C)  fusion of helium nuclei to form carbon and oxygen 
D)  fusion of hydrogen nuclei to form helium

Question 3

Pulsating X-ray sources are believed to be:

Accepted Answer

A)  white dwarfs with intense magnetic fields; the X-rays are generated by flares like those on the Sun only much stronger. 
B)  spinning neutron stars in binary systems, emitting X-rays because of mass transfer onto the neutron star from its normal companion. 
C)  the same as regular (optical) pulsars but observed in X-rays. 
D)  black holes in binary systems, with an accretion disk around the black hole emitting X-rays. 
A)  white dwarfs with intense magnetic fields; the X-rays are generated by flares like those on the Sun only much stronger. 
B)  spinning neutron stars in binary systems, emitting X-rays because of mass transfer onto the neutron star from its normal companion. 
C)  the same as regular (optical) pulsars but observed in X-rays. 
D)  black holes in binary systems, with an accretion disk around the black hole emitting X-rays.

Question 4

During which phase of a low-mass star's life does helium shell fusion occur?

Accepted Answer

A)  main sequence 
B)  asymptotic giant branch 
C)  first red giant 
D)  horizontal branch 
A)  main sequence 
B)  asymptotic giant branch 
C)  first red giant 
D)  horizontal branch

Question 5

Around 2 million years ago,astronomers believe,Earth's ozone layer may have been significantly damaged,leading to radiation damage to life on Earth.What is believed to be the cause of the damage?

Accepted Answer

A)  An OB association may have been close enough that a supernova flooded the Earth with intense radiation. 
B)  The Sun went through its T Tauri expansion. 
C)  The Sun sent out a ring of material as it formed a planetary nebula. 
D)  The Gum Supernova erupted. 
A)  An OB association may have been close enough that a supernova flooded the Earth with intense radiation. 
B)  The Sun went through its T Tauri expansion. 
C)  The Sun sent out a ring of material as it formed a planetary nebula. 
D)  The Gum Supernova erupted.

Question 6

The spectrum of a Type Ia supernova can be identified because it lacks evidence of:

Accepted Answer

A)  hydrogen. 
B)  carbon. 
C)  nickel. 
D)  cobalt. 
A)  hydrogen. 
B)  carbon. 
C)  nickel. 
D)  cobalt.

Question 7

In the collapsing core of a high-mass star just before a supernova explosion occurs,the density is about that:

Accepted Answer

A)  of degenerate gases in white dwarfs, about 10⁹ kg/m³. 
B)  of nuclear matter in a normal nucleus, about 4 × 10¹⁷ kg/m³. 
C)  at the center of the Sun, about 1.5 × 10⁵ kg/m³. 
D)  of iron, 7.5 × 10³ kg/m³. 
A)  of degenerate gases in white dwarfs, about 10⁹ kg/m³. 
B)  of nuclear matter in a normal nucleus, about 4 × 10¹⁷ kg/m³. 
C)  at the center of the Sun, about 1.5 × 10⁵ kg/m³. 
D)  of iron, 7.5 × 10³ kg/m³.

Question 8

The intense X-rays emitted by a suspected black hole are generated by what physical mechanism?

Accepted Answer

A)  the blueshifting of light emitted by hot gas into the X-ray region of the electromagnetic spectrum by the extreme speed of the gas moving into the black hole 
B)  induced emission in atoms by the intense gravitational field as material moves toward the black hole 
C)  compressional heating as material moves into the hole 
D)  the deceleration of matter as it abruptly stops at the event horizon of the black hole 
A)  the blueshifting of light emitted by hot gas into the X-ray region of the electromagnetic spectrum by the extreme speed of the gas moving into the black hole 
B)  induced emission in atoms by the intense gravitational field as material moves toward the black hole 
C)  compressional heating as material moves into the hole 
D)  the deceleration of matter as it abruptly stops at the event horizon of the black hole

Question 9

Light leaving the surface of a neutron star is strongly redshifted.What name is given to this effect?

Accepted Answer

A)  cosmological redshift 
B)  gravitational redshift 
C)  Zeeman effect 
D)  Doppler shift 
A)  cosmological redshift 
B)  gravitational redshift 
C)  Zeeman effect 
D)  Doppler shift

Question 10

What property of matter does general relativity address that is NOT included in special relativity?

Accepted Answer

A)  acceleration 
B)  color 
C)  mass 
D)  temperature 
A)  acceleration 
B)  color 
C)  mass 
D)  temperature

Question 11

In which order do the stages of core nuclear fusion occur in the evolution of a massive star?

Accepted Answer

A)  carbon, helium, oxygen, neon 
B)  helium, carbon, neon, oxygen 
C)  helium, oxygen, carbon, neon 
D)  helium, carbon, oxygen, neon 
A)  carbon, helium, oxygen, neon 
B)  helium, carbon, neon, oxygen 
C)  helium, oxygen, carbon, neon 
D)  helium, carbon, oxygen, neon

Question 12

One newly discovered type of neutron star is the rotating radio transient,which periodically emits a very brief burst of intense radio radiation.What is our BEST explanation,at present,for this phenomenon?

Accepted Answer

A)  Rotating radio transients are very young neutron stars, and they emit radio radiation in response to a "settling down" deep in their interiors. 
B)  Rotating radio transients are very old neutron stars. They have cooled off until their temperatures are low enough to emit radiation in the radio range. 
C)  Rotating radio transients are neutron stars in eclipsing binary systems, and the output of radio radiation is periodically eclipsed by the companion. 
D)  Rotating radio transients are pulsars whose rotation rate has slowed down to about one rotation every 0.4 to 10 seconds. 
A)  Rotating radio transients are very young neutron stars, and they emit radio radiation in response to a "settling down" deep in their interiors. 
B)  Rotating radio transients are very old neutron stars. They have cooled off until their temperatures are low enough to emit radiation in the radio range. 
C)  Rotating radio transients are neutron stars in eclipsing binary systems, and the output of radio radiation is periodically eclipsed by the companion. 
D)  Rotating radio transients are pulsars whose rotation rate has slowed down to about one rotation every 0.4 to 10 seconds.

Question 13

What will be the mass of the Sun at the end of its asymptotic giant branch (AGB)phase,due to mass loss to space by its stellar wind?

Accepted Answer

A)  still almost 1 solar mass since mass loss is negligible for a low-mass star like the Sun 
B)  between 0.1 and 0.2 solar mass 
C)  about 0.8 solar mass 
D)  about 0.5 solar mass 
A)  still almost 1 solar mass since mass loss is negligible for a low-mass star like the Sun 
B)  between 0.1 and 0.2 solar mass 
C)  about 0.8 solar mass 
D)  about 0.5 solar mass

Question 14

Suppose you see a news announcement that astronomers have discovered a nova in a distant galaxy.What do you immediately know about the star that gave rise to this nova?

Accepted Answer

A)  The star is a white dwarf in a binary system in which the other star fills its Roche lobe. 
B)  The star is a neutron star in a binary system in which the other star is a white dwarf. 
C)  The star is a neutron star in a binary system in which the other star fills its Roche lobe. 
D)  The star is a black hole in a binary system in which the other star fills its Roche lobe. 
A)  The star is a white dwarf in a binary system in which the other star fills its Roche lobe. 
B)  The star is a neutron star in a binary system in which the other star is a white dwarf. 
C)  The star is a neutron star in a binary system in which the other star fills its Roche lobe. 
D)  The star is a black hole in a binary system in which the other star fills its Roche lobe.

Question 15

Some objects in the Milky Way Galaxy are observed to be emitting two oppositely directed jets of material.These gas jets are believed to be:

Accepted Answer

A)  energetic, charged particles ejected along the magnetic axes of a rotating neutron star. 
B)  material squirted out along the rotation axis of an accretion disk around a neutron star in a binary star system. 
C)  material transferred onto the surface of a white dwarf in a binary star system, then subsequently blasted into space by runaway thermonuclear fusion reactions. 
D)  material expelled from the far side of the companion star in a binary system, repelled by magnetic interaction with the pulsar. 
A)  energetic, charged particles ejected along the magnetic axes of a rotating neutron star. 
B)  material squirted out along the rotation axis of an accretion disk around a neutron star in a binary star system. 
C)  material transferred onto the surface of a white dwarf in a binary star system, then subsequently blasted into space by runaway thermonuclear fusion reactions. 
D)  material expelled from the far side of the companion star in a binary system, repelled by magnetic interaction with the pulsar.

Question 16

Pulsars are rotating neutron stars that emit beams of electromagnetic radiation that sweep around the universe like rotating lighthouse beams.The charged particles that emit these beams are believed to be:

Accepted Answer

A)  "charmed" mesons and other exotic particles that on Earth exist only in laboratories. 
B)  iron and other nuclei pulled from the neutron star's crust by its intense magnetic fields. 
C)  plasma (ionized gas) spiraling onto the neutron star from a normal stellar companion. 
D)  electrons and protons accelerated by the neutron star's intense magnetic fields. 
A)  "charmed" mesons and other exotic particles that on Earth exist only in laboratories. 
B)  iron and other nuclei pulled from the neutron star's crust by its intense magnetic fields. 
C)  plasma (ionized gas) spiraling onto the neutron star from a normal stellar companion. 
D)  electrons and protons accelerated by the neutron star's intense magnetic fields.

Question 17

As you are investigating a black hole from a safe distance,a rivet pops out of the tailfin on your spaceship and falls toward the black hole.Will you ever see the rivet enter the event horizon?

Accepted Answer

A)  Yes. However, it will be so blueshifted that you would need X-ray eyes to see it. 
B)  No. It will be compressed to zero size and disappear from sight before it reaches the event horizon. 
C)  Yes. You will see it fall faster and faster until it disappears as it falls through the event horizon. 
D)  No. It will appear to stop and hover forever before entering the event horizon. 
A)  Yes. However, it will be so blueshifted that you would need X-ray eyes to see it. 
B)  No. It will be compressed to zero size and disappear from sight before it reaches the event horizon. 
C)  Yes. You will see it fall faster and faster until it disappears as it falls through the event horizon. 
D)  No. It will appear to stop and hover forever before entering the event horizon.

Question 18

After the material in the core of a massive star has been converted to iron by thermonuclear reactions,further energy can be released to heat the core only by:

Accepted Answer

A)  gravitational contraction. 
B)  nuclear fission, or splitting of nuclei. 
C)  the absorption of neutrinos. 
D)  thermonuclear fusion of iron into heavier elements. 
A)  gravitational contraction. 
B)  nuclear fission, or splitting of nuclei. 
C)  the absorption of neutrinos. 
D)  thermonuclear fusion of iron into heavier elements.

Question 19

Which statement is NOT a consequence of the postulates of special relativity?

Accepted Answer

A)  The mass of an object moving with respect to an observer is larger than the mass measured by a different observer who is at rest with respect to the object. 
B)  A clock moving with respect to an observer ticks more slowly than when measured by an observer who is moving along with the clock. 
C)  The length of an object moving with respect to an observer is shorter than it is when measured by a different observer moving along with the object. 
D)  The wavelength emitted from a source moving with respect to an observer is different from the wavelength measured by an observer who is moving along with the source. 
A)  The mass of an object moving with respect to an observer is larger than the mass measured by a different observer who is at rest with respect to the object. 
B)  A clock moving with respect to an observer ticks more slowly than when measured by an observer who is moving along with the clock. 
C)  The length of an object moving with respect to an observer is shorter than it is when measured by a different observer moving along with the object. 
D)  The wavelength emitted from a source moving with respect to an observer is different from the wavelength measured by an observer who is moving along with the source.

Question 20

What new method has recently provided astronomers with new information about the interiors of stars,for example,the collapse of the inner core of a star undergoing supernova explosion or the interior of the Sun?

Accepted Answer

A)  X-ray astronomy and photography 
B)  radio astronomy 
C)  visible light spectroscopy 
D)  neutrino astronomy 
A)  X-ray astronomy and photography 
B)  radio astronomy 
C)  visible light spectroscopy 
D)  neutrino astronomy

Evidence for the conclusion that the longer-living gamma-ray bursters are very distant comes from the:

What is the last nuclear fusion stage in the life of a low-mass star like the Sun?

Pulsating X-ray sources are believed to be:

During which phase of a low-mass star's life does helium shell fusion occur?

Around 2 million years ago,astronomers believe,Earth's ozone layer may have been significantly damaged,leading to radiation damage to life on Earth.What is believed to be the cause of the damage?

The spectrum of a Type Ia supernova can be identified because it lacks evidence of:

In the collapsing core of a high-mass star just before a supernova explosion occurs,the density is about that:

The intense X-rays emitted by a suspected black hole are generated by what physical mechanism?

Light leaving the surface of a neutron star is strongly redshifted.What name is given to this effect?

What property of matter does general relativity address that is NOT included in special relativity?

In which order do the stages of core nuclear fusion occur in the evolution of a massive star?

One newly discovered type of neutron star is the rotating radio transient,which periodically emits a very brief burst of intense radio radiation.What is our BEST explanation,at present,for this phenomenon?

What will be the mass of the Sun at the end of its asymptotic giant branch (AGB)phase,due to mass loss to space by its stellar wind?

Suppose you see a news announcement that astronomers have discovered a nova in a distant galaxy.What do you immediately know about the star that gave rise to this nova?

Some objects in the Milky Way Galaxy are observed to be emitting two oppositely directed jets of material.These gas jets are believed to be:

Pulsars are rotating neutron stars that emit beams of electromagnetic radiation that sweep around the universe like rotating lighthouse beams.The charged particles that emit these beams are believed to be:

As you are investigating a black hole from a safe distance,a rivet pops out of the tailfin on your spaceship and falls toward the black hole.Will you ever see the rivet enter the event horizon?

After the material in the core of a massive star has been converted to iron by thermonuclear reactions,further energy can be released to heat the core only by:

Which statement is NOT a consequence of the postulates of special relativity?

What new method has recently provided astronomers with new information about the interiors of stars,for example,the collapse of the inner core of a star undergoing supernova explosion or the interior of the Sun?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Galaxies

Cosmology

Astrobiology

Filters

Exam 12: The Deaths and Remnants of Stars

Evidence for the conclusion that the longer-living gamma-ray bursters are very distant comes from the:

What is the last nuclear fusion stage in the life of a low-mass star like the Sun?

Pulsating X-ray sources are believed to be:

During which phase of a low-mass star's life does helium shell fusion occur?

Around 2 million years ago,astronomers believe,Earth's ozone layer may have been significantly damaged,leading to radiation damage to life on Earth.What is believed to be the cause of the damage?

The spectrum of a Type Ia supernova can be identified because it lacks evidence of:

In the collapsing core of a high-mass star just before a supernova explosion occurs,the density is about that:

The intense X-rays emitted by a suspected black hole are generated by what physical mechanism?

Light leaving the surface of a neutron star is strongly redshifted.What name is given to this effect?

What property of matter does general relativity address that is NOT included in special relativity?

In which order do the stages of core nuclear fusion occur in the evolution of a massive star?

One newly discovered type of neutron star is the rotating radio transient,which periodically emits a very brief burst of intense radio radiation.What is our BEST explanation,at present,for this phenomenon?

What will be the mass of the Sun at the end of its asymptotic giant branch (AGB)phase,due to mass loss to space by its stellar wind?

Suppose you see a news announcement that astronomers have discovered a nova in a distant galaxy.What do you immediately know about the star that gave rise to this nova?

Some objects in the Milky Way Galaxy are observed to be emitting two oppositely directed jets of material.These gas jets are believed to be:

Pulsars are rotating neutron stars that emit beams of electromagnetic radiation that sweep around the universe like rotating lighthouse beams.The charged particles that emit these beams are believed to be:

As you are investigating a black hole from a safe distance,a rivet pops out of the tailfin on your spaceship and falls toward the black hole.Will you ever see the rivet enter the event horizon?

After the material in the core of a massive star has been converted to iron by thermonuclear reactions,further energy can be released to heat the core only by:

Which statement is NOT a consequence of the postulates of special relativity?

What new method has recently provided astronomers with new information about the interiors of stars,for example,the collapse of the inner core of a star undergoing supernova explosion or the interior of the Sun?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Galaxies

Cosmology

Astrobiology

Filters