Question 1

Consider a group of stars with masses up to 8 times the mass of the Sun. Stars of which masses will pass along the asymptotic giant branch?

Accepted Answer

A)  less than 0.4 MSun 
B)  0.4 MSun to 2 MSun only 
C)  2 MSun to 8 MSun only 
D)  all stars 0.4 MSun to 8 MSun 
A)  less than 0.4 MSun 
B)  0.4 MSun to 2 MSun only 
C)  2 MSun to 8 MSun only 
D)  all stars 0.4 MSun to 8 MSun

Question 2

How does a white dwarf generate its energy?

Accepted Answer

A)  It no longer generates energy but is slowly cooling as it radiates away its heat. 
B)  Nuclear fusion of hydrogen into helium is producing energy in its core. 
C)  Nuclear fission of heavy elements in the central core is releasing energy. 
D)  Gravitational potential energy is released as the star slowly contracts. 
A)  It no longer generates energy but is slowly cooling as it radiates away its heat. 
B)  Nuclear fusion of hydrogen into helium is producing energy in its core. 
C)  Nuclear fission of heavy elements in the central core is releasing energy. 
D)  Gravitational potential energy is released as the star slowly contracts.

Question 3

Where should an astronomer look in order to find a core-collapse supernova?

Accepted Answer

A)  in a globular cluster 
B)  near a star-forming region 
C)  in a binary star system 
D)  near a black hole 
A)  in a globular cluster 
B)  near a star-forming region 
C)  in a binary star system 
D)  near a black hole

Question 4

What are the main products of helium nuclear fusion in red giant stars?

Accepted Answer

A)  hydrogen nuclei by nuclear fission 
B)  energy from the complete transformation of the mass of helium to energy 
C)  iron nuclei 
D)  carbon and oxygen nuclei 
A)  hydrogen nuclei by nuclear fission 
B)  energy from the complete transformation of the mass of helium to energy 
C)  iron nuclei 
D)  carbon and oxygen nuclei

Question 5

The periods of MOST pulsars _____ with time.

Accepted Answer

A)  increase 
B)  decrease 
C)  remain constant 
D)  alternately increase and decrease 
A)  increase 
B)  decrease 
C)  remain constant 
D)  alternately increase and decrease

Question 6

Which of these types of stars or stellar remnants can have a mass no larger than about 1.4 times the mass of the Sun, or else they will collapse under their own gravity?

Accepted Answer

A)  red giants 
B)  black holes 
C)  neutron stars 
D)  white dwarfs 
A)  red giants 
B)  black holes 
C)  neutron stars 
D)  white dwarfs

Question 7

The energy-generation process inside a white dwarf star is

Accepted Answer

A)  the combining of protons and electrons to form neutrons within its core. 
B)  hydrogen fusion. 
C)  nonexistent-a white dwarf star is simply cooling by radiating its original heat. 
D)  the helium flash-very efficient and rapid helium fusion. 
A)  the combining of protons and electrons to form neutrons within its core. 
B)  hydrogen fusion. 
C)  nonexistent-a white dwarf star is simply cooling by radiating its original heat. 
D)  the helium flash-very efficient and rapid helium fusion.

Question 8

Which of these is MOST likely to occur inside a binary system containing a white dwarf with a mass considerably below 1.4 MSun?

Accepted Answer

A)  a nova 
B)  a Type Ia supernova 
C)  a Type II supernova 
D)  a supernova remnant 
A)  a nova 
B)  a Type Ia supernova 
C)  a Type II supernova 
D)  a supernova remnant

Question 9

Observing neutrinos from SN 1987A was a substantial part of the study of the supernova. Which of these statements about these neutrinos is NOT true?

Accepted Answer

A)  The neutrinos arrived at Earth before the visible light. 
B)  Neutrino detectors using Cherenkov radiation need not be pointed at their targets, so the neutrinos could be detected even though they were unexpected. 
C)  Only neutrino detectors in the southern hemisphere were able to record the event since the Large Magellanic Cloud is only visible in the southern hemisphere. 
D)  The discovery of neutrinos from SN 1987A provided strong support for the theory that supernovae are caused by the collapse of a star's core. 
A)  The neutrinos arrived at Earth before the visible light. 
B)  Neutrino detectors using Cherenkov radiation need not be pointed at their targets, so the neutrinos could be detected even though they were unexpected. 
C)  Only neutrino detectors in the southern hemisphere were able to record the event since the Large Magellanic Cloud is only visible in the southern hemisphere. 
D)  The discovery of neutrinos from SN 1987A provided strong support for the theory that supernovae are caused by the collapse of a star's core.

Question 10

The very strong magnetic field on a neutron star is created by

Accepted Answer

A)  the collapse of the star, which significantly intensifies the original weak magnetic field of the star. 
B)  differential rotation of the star, with the equator rotating faster than the poles, similar to sunspot formation. 
C)  a burst of neutrinos produced by the supernova explosion, the equivalent of a very large electrical current flowing for a short time. 
D)  turbulence in the electrical plasmas during the collapse of the star; the original star would have had no magnetic field. 
A)  the collapse of the star, which significantly intensifies the original weak magnetic field of the star. 
B)  differential rotation of the star, with the equator rotating faster than the poles, similar to sunspot formation. 
C)  a burst of neutrinos produced by the supernova explosion, the equivalent of a very large electrical current flowing for a short time. 
D)  turbulence in the electrical plasmas during the collapse of the star; the original star would have had no magnetic field.

Question 11

Relative to its luminosity as a supergiant, the luminosity of a typical supernova star during the initial phases of the explosion could increase by a factor of

Accepted Answer

A)  108. 
B)  106. 
C)  2 to 3, since the star is already very bright. 
D)  102. 
A)  108. 
B)  106. 
C)  2 to 3, since the star is already very bright. 
D)  102.

Question 12

One newly discovered type of neutron star is the "rotating radio transient," which occasionally emits a very brief burst of intense radio radiation. What is the 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

The duration of the oxygen-fusing stage in the core of a massive star is considerably shorter than the duration of the carbon-fusing stage. One main reason for this is that

Accepted Answer

A)  carbon is a solid, while oxygen is a gas. 
B)  oxygen fusion does not begin until the contracting core has reached a higher temperature than the temperature at which carbon fusion is possible. 
C)  the electron degeneracy inhibits the carbon reaction, but it has been removed by the time oxygen fusion begins. 
D)  there are more fusion shells surrounding the oxygen fusion core than there are around the carbon fusion core. The shells prevent the escape of oxygen before it can fuse. 
A)  carbon is a solid, while oxygen is a gas. 
B)  oxygen fusion does not begin until the contracting core has reached a higher temperature than the temperature at which carbon fusion is possible. 
C)  the electron degeneracy inhibits the carbon reaction, but it has been removed by the time oxygen fusion begins. 
D)  there are more fusion shells surrounding the oxygen fusion core than there are around the carbon fusion core. The shells prevent the escape of oxygen before it can fuse.

Question 14

When a massive star collapses into a Type II supernova, elements heavier than iron are created. But the amounts of these elements that survive such a collapse are not sufficient to account for the amounts seen in the universe. Where are/were many of them likely produced?

Accepted Answer

A)  Type Ia supernovae 
B)  the original Big Bang at the origin of the universe 
C)  collisions of neutron stars 
D)  nucleosynthesis in the cores of smaller but more numerous stars, like the Sun 
A)  Type Ia supernovae 
B)  the original Big Bang at the origin of the universe 
C)  collisions of neutron stars 
D)  nucleosynthesis in the cores of smaller but more numerous stars, like the Sun

Question 15

MOST supernova remnants have been discovered by observing in which wavelength region?

Accepted Answer

A)  gamma ray 
B)  ultraviolet 
C)  visible 
D)  radio 
A)  gamma ray 
B)  ultraviolet 
C)  visible 
D)  radio

Question 16

The 2004 discovery of two pulsars in orbit around their common center of mass is significant because it gives a unique opportunity to study some of the predictions of

Accepted Answer

A)  Kepler's laws. 
B)  the theory of angular momentum. 
C)  the general theory of relativity. 
D)  the special theory of relativity. 
A)  Kepler's laws. 
B)  the theory of angular momentum. 
C)  the general theory of relativity. 
D)  the special theory of relativity.

Question 17

Can a white dwarf explode?

Accepted Answer

A)  Yes, but only if another star collides with it; stars are so far apart in space that this is unlikely ever to have happened in the Galaxy. 
B)  Yes, but only if it is in a binary star system. 
C)  Yes, but only if nuclear reactions in the white dwarf core reach the stage of silicon fusion, producing iron. 
D)  No. White dwarfs are held up by electron degeneracy pressure, and this configuration is stable against collapse or explosion. 
A)  Yes, but only if another star collides with it; stars are so far apart in space that this is unlikely ever to have happened in the Galaxy. 
B)  Yes, but only if it is in a binary star system. 
C)  Yes, but only if nuclear reactions in the white dwarf core reach the stage of silicon fusion, producing iron. 
D)  No. White dwarfs are held up by electron degeneracy pressure, and this configuration is stable against collapse or explosion.

Question 18

Low-mass stars can ascend the H-R diagram in two evolutionary phases called giant phases. What is the difference between them?

Accepted Answer

A)  In the first, the primary production of energy is from hydrogen burning in the core. In the second, the primary production of energy is from helium burning in the core. 
B)  In the first, the primary production of energy is from hydrogen burning in a shell around the core. In the second, the primary production of energy is from helium burning in a shell around the core. 
C)  In the first, the star's track on the Hertzsprung-Russell diagram lies along the red-giant branch. In the second, the track lies along the horizontal branch. 
D)  During the first red-giant phase, the star moves up and to the right along the red-giant branch. During the second red-giant phase the star's track is down and to the left along the same red-giant branch. 
A)  In the first, the primary production of energy is from hydrogen burning in the core. In the second, the primary production of energy is from helium burning in the core. 
B)  In the first, the primary production of energy is from hydrogen burning in a shell around the core. In the second, the primary production of energy is from helium burning in a shell around the core. 
C)  In the first, the star's track on the Hertzsprung-Russell diagram lies along the red-giant branch. In the second, the track lies along the horizontal branch. 
D)  During the first red-giant phase, the star moves up and to the right along the red-giant branch. During the second red-giant phase the star's track is down and to the left along the same red-giant branch.

Question 19

Type II supernovae show prominent lines of hydrogen in their spectra, whereas hydrogen lines are absent in spectra of Type Ia supernovae. Explain. (Hint: Think about the type of star that gives rise to each of the two types of supernova.)

Accepted Answer

A)  Massive stars contain large amounts of hydrogen, whereas white dwarfs are mostly carbon and oxygen. 
B)  White dwarfs have a thick surface layer of hydrogen, whereas neutron stars contain no hydrogen at all. 
C)  Massive stars have fused all their hydrogen into heavier elements, whereas low-mass stars still have large hydrogen-rich envelopes. 
D)  Massive stars contain large amounts of hydrogen, whereas neutron stars contain no hydrogen at all. 
A)  Massive stars contain large amounts of hydrogen, whereas white dwarfs are mostly carbon and oxygen. 
B)  White dwarfs have a thick surface layer of hydrogen, whereas neutron stars contain no hydrogen at all. 
C)  Massive stars have fused all their hydrogen into heavier elements, whereas low-mass stars still have large hydrogen-rich envelopes. 
D)  Massive stars contain large amounts of hydrogen, whereas neutron stars contain no hydrogen at all.

Question 20

Which type of dwarf is largest?

Accepted Answer

A)  white dwarf 
B)  red dwarf 
C)  brown dwarf 
D)  All are about the same size. 
A)  white dwarf 
B)  red dwarf 
C)  brown dwarf 
D)  All are about the same size.

Consider a group of stars with masses up to 8 times the mass of the Sun. Stars of which masses will pass along the asymptotic giant branch?

How does a white dwarf generate its energy?

Where should an astronomer look in order to find a core-collapse supernova?

What are the main products of helium nuclear fusion in red giant stars?

The periods of MOST pulsars _____ with time.

Which of these types of stars or stellar remnants can have a mass no larger than about 1.4 times the mass of the Sun, or else they will collapse under their own gravity?

The energy-generation process inside a white dwarf star is

Which of these is MOST likely to occur inside a binary system containing a white dwarf with a mass considerably below 1.4 M_Sun?

Observing neutrinos from SN 1987A was a substantial part of the study of the supernova. Which of these statements about these neutrinos is NOT true?

The very strong magnetic field on a neutron star is created by

Relative to its luminosity as a supergiant, the luminosity of a typical supernova star during the initial phases of the explosion could increase by a factor of

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

The duration of the oxygen-fusing stage in the core of a massive star is considerably shorter than the duration of the carbon-fusing stage. One main reason for this is that

When a massive star collapses into a Type II supernova, elements heavier than iron are created. But the amounts of these elements that survive such a collapse are not sufficient to account for the amounts seen in the universe. Where are/were many of them likely produced?

MOST supernova remnants have been discovered by observing in which wavelength region?

The 2004 discovery of two pulsars in orbit around their common center of mass is significant because it gives a unique opportunity to study some of the predictions of

Can a white dwarf explode?

Low-mass stars can ascend the H-R diagram in two evolutionary phases called giant phases. What is the difference between them?

Type II supernovae show prominent lines of hydrogen in their spectra, whereas hydrogen lines are absent in spectra of Type Ia supernovae. Explain. (Hint: Think about the type of star that gives rise to each of the two types of supernova.)

Which type of dwarf is largest?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 14: The Death of Stars

Consider a group of stars with masses up to 8 times the mass of the Sun. Stars of which masses will pass along the asymptotic giant branch?

How does a white dwarf generate its energy?

Where should an astronomer look in order to find a core-collapse supernova?

What are the main products of helium nuclear fusion in red giant stars?

The periods of MOST pulsars _____ with time.

Which of these types of stars or stellar remnants can have a mass no larger than about 1.4 times the mass of the Sun, or else they will collapse under their own gravity?

The energy-generation process inside a white dwarf star is

Which of these is MOST likely to occur inside a binary system containing a white dwarf with a mass considerably below 1.4 MSun?

Observing neutrinos from SN 1987A was a substantial part of the study of the supernova. Which of these statements about these neutrinos is NOT true?

The very strong magnetic field on a neutron star is created by

Relative to its luminosity as a supergiant, the luminosity of a typical supernova star during the initial phases of the explosion could increase by a factor of

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

The duration of the oxygen-fusing stage in the core of a massive star is considerably shorter than the duration of the carbon-fusing stage. One main reason for this is that

When a massive star collapses into a Type II supernova, elements heavier than iron are created. But the amounts of these elements that survive such a collapse are not sufficient to account for the amounts seen in the universe. Where are/were many of them likely produced?

MOST supernova remnants have been discovered by observing in which wavelength region?

The 2004 discovery of two pulsars in orbit around their common center of mass is significant because it gives a unique opportunity to study some of the predictions of

Can a white dwarf explode?

Low-mass stars can ascend the H-R diagram in two evolutionary phases called giant phases. What is the difference between them?

Type II supernovae show prominent lines of hydrogen in their spectra, whereas hydrogen lines are absent in spectra of Type Ia supernovae. Explain. (Hint: Think about the type of star that gives rise to each of the two types of supernova.)

Which type of dwarf is largest?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Which of these is MOST likely to occur inside a binary system containing a white dwarf with a mass considerably below 1.4 M_Sun?