Question 1

At the end of its life, the remaining core of this star will be left behind as

Accepted Answer

A)  a white dwarf made primarily of carbon and oxygen. 
B)  a white dwarf made primarily of silicon and iron. 
C)  a neutron star. 
D)  a black hole. 
E)  a supernova. 
A)  a white dwarf made primarily of carbon and oxygen. 
B)  a white dwarf made primarily of silicon and iron. 
C)  a neutron star. 
D)  a black hole. 
E)  a supernova.

Question 2

The helium fusion process works by fusing two helium nuclei into one beryllium nucleus.

Accepted Answer

A) True 
 B)False

Question 3

What is a planetary nebula?

Accepted Answer

A)  a disk of gas surrounding a protostar that may form into planets 
B)  what is left of its planets after a low-mass star has ended its life 
C)  the expanding shell of gas that is no longer gravitationally bound to the remnant of a low-mass star 
D)  the molecular cloud from which protostars form 
E)  the expanding shell of gas that is left when a white dwarf explodes as a supernova 
A)  a disk of gas surrounding a protostar that may form into planets 
B)  what is left of its planets after a low-mass star has ended its life 
C)  the expanding shell of gas that is no longer gravitationally bound to the remnant of a low-mass star 
D)  the molecular cloud from which protostars form 
E)  the expanding shell of gas that is left when a white dwarf explodes as a supernova

Question 4

What is the lifetime of a star of 0.1 solar masses and a luminosity of 0.01 that of the Sun. Assume the lifetime of the Sun is 10 billion years.

Accepted Answer

A)  10 million years 
B)  10 trillion years 
C)  10 billion years 
D)  100 billion years 
E)  This star will never start hydrogen fusion reactions because it is not massive enough. 
A)  10 million years 
B)  10 trillion years 
C)  10 billion years 
D)  100 billion years 
E)  This star will never start hydrogen fusion reactions because it is not massive enough.

Question 5

What is a helium flash?

Accepted Answer

A)  The sudden onset of helium fusion in the core of a low-mass star 
B)  The ignition of helium shell burning in a high-mass star with a carbon core 
C)  A sudden brightening of a low-mass star, detectable from Earth by observing spectral lines of helium 
D)  It is another name for the helium fusion reaction. 
A)  The sudden onset of helium fusion in the core of a low-mass star 
B)  The ignition of helium shell burning in a high-mass star with a carbon core 
C)  A sudden brightening of a low-mass star, detectable from Earth by observing spectral lines of helium 
D)  It is another name for the helium fusion reaction.

Question 6

There is no limit to the mass with which a star can be born.

Accepted Answer

A) True 
 B)False

Question 7

Which type of star spends the shortest time as a main sequence star?

Accepted Answer

A)  O star 
B)  M star 
C)  B star 
D)  G star 
A)  O star 
B)  M star 
C)  B star 
D)  G star

Question 8

What will happen in the Sun immediately after it has exhausted its supply of hydrogen in its core?

Accepted Answer

A)  The helium core will shrink and heat; a shell of hydrogen will start fusing. 
B)  The helium core will shrink, heat, and start fusing helium to carbon. 
C)  The core will collapse and a supernova will result. 
D)  The Sun will turn into a white dwarf and cool off forever. 
A)  The helium core will shrink and heat; a shell of hydrogen will start fusing. 
B)  The helium core will shrink, heat, and start fusing helium to carbon. 
C)  The core will collapse and a supernova will result. 
D)  The Sun will turn into a white dwarf and cool off forever.

Question 9

According to this plot, which is the third most abundant element in the universe?

Accepted Answer

A)  Hydrogen 
B)  Boron 
C)  Oxygen 
D)  Lithium 
E)  Helium 
A)  Hydrogen 
B)  Boron 
C)  Oxygen 
D)  Lithium 
E)  Helium

Question 10

No stars are expected with masses greater than 150 times our Sun because

Accepted Answer

A)  molecular clouds do not have enough material to form such massive stars. 
B)  they would fragment into binary stars because of their rapid rotation. 
C)  they would generate so much power that they would blow themselves apart. 
D)  they would shine exclusively at X-ray wavelengths and would be difficult to detect. 
E)  they would be too massive for hydrogen fusion to occur in their cores. 
A)  molecular clouds do not have enough material to form such massive stars. 
B)  they would fragment into binary stars because of their rapid rotation. 
C)  they would generate so much power that they would blow themselves apart. 
D)  they would shine exclusively at X-ray wavelengths and would be difficult to detect. 
E)  they would be too massive for hydrogen fusion to occur in their cores.

Question 11

Which type of star spends the longest time as a protostar?

Accepted Answer

A)  O star 
B)  B star 
C)  M star 
D)  G star 
A)  O star 
B)  B star 
C)  M star 
D)  G star

Question 12

Carbon fusion occur in high-mass stars but not in low-mass stars because ________.

Accepted Answer

A)  the cores of low-mass stars never get hot enough for carbon fusion 
B)  the cores of low-mass stars never contain significant amounts of carbon 
C)  only high-mass stars do fusion by the CNO cycle 
D)  carbon fusion can occur only in the stars known as carbon stars 
A)  the cores of low-mass stars never get hot enough for carbon fusion 
B)  the cores of low-mass stars never contain significant amounts of carbon 
C)  only high-mass stars do fusion by the CNO cycle 
D)  carbon fusion can occur only in the stars known as carbon stars

Question 13

Historical Supernova: You find an ancient Chinese text that speaks of a "new star" briefly visible in the constellation Sagittarius in the year 1000 B.C. You suspect that the reference is to a supernova explosion. Design an observing program to provide scientific evidence for this hypothesis. What object or objects would you look for in the sky today? What wavelengths of electromagnetic radiation would you use? How would you be sure any object you found exploded (as seen from the Earth) nearly 3000 years ago?

Accepted Answer

To provide scientific evidence for the h

Question 14

What is a planetary nebula?

Accepted Answer

A)  Gas ejected from a low-mass star in the final stage of its life 
B)  Gas created from the remains of planets that once orbited a dead star 
C)  Interstellar gas from which planets are likely to form in the not-too-distant future 
D)  The remains of a high-mass star that has exploded 
A)  Gas ejected from a low-mass star in the final stage of its life 
B)  Gas created from the remains of planets that once orbited a dead star 
C)  Interstellar gas from which planets are likely to form in the not-too-distant future 
D)  The remains of a high-mass star that has exploded

Question 15

What is the approximate range of masses that newborn main sequence stars can have?

Accepted Answer

A)  0.1 to 150 solar masses 
B)  0.001 to 150 solar masses 
C)  0.1 to 1,000 solar masses 
D)  0.001 to 10 solar masses 
E)  0.1 to 10 solar masses 
A)  0.1 to 150 solar masses 
B)  0.001 to 150 solar masses 
C)  0.1 to 1,000 solar masses 
D)  0.001 to 10 solar masses 
E)  0.1 to 10 solar masses

Question 16

What is a protostar?

Accepted Answer

A)  A star that is still in the process of forming 
B)  A star that has planets 
C)  An intermediate-mass star 
D)  A star in its final stage of life 
A)  A star that is still in the process of forming 
B)  A star that has planets 
C)  An intermediate-mass star 
D)  A star in its final stage of life

Question 17

Which element has the lowest mass per nuclear particle and therefore cannot release energy by either fusion or fission?

Accepted Answer

A)  hydrogen 
B)  oxygen 
C)  silicon 
D)  iron 
A)  hydrogen 
B)  oxygen 
C)  silicon 
D)  iron

Question 18

What happens when the gravity of a massive star is able to overcome neutron degeneracy pressure?

Accepted Answer

A)  The core contracts and becomes a white dwarf. 
B)  The core contracts and becomes a ball of neutrons. 
C)  The core contracts and becomes a black hole. 
D)  The star explodes violently, leaving nothing behind. 
E)  Gravity is not able to overcome neutron degeneracy pressure. 
A)  The core contracts and becomes a white dwarf. 
B)  The core contracts and becomes a ball of neutrons. 
C)  The core contracts and becomes a black hole. 
D)  The star explodes violently, leaving nothing behind. 
E)  Gravity is not able to overcome neutron degeneracy pressure.

Question 19

Which star has the shortest lifetime?

Accepted Answer

A)  O star 
B)  G star 
C)  A star 
D)  M star 
A)  O star 
B)  G star 
C)  A star 
D)  M star

Question 20

Why is Supernova 1987A particularly important to astronomers?

Accepted Answer

A)  It occurred only a few dozen light-years from Earth. 
B)  It provided the first observational evidence that supernovae actually occur. 
C)  It provided the first evidence that neutron stars exist. 
D)  It was the first supernova detected in nearly 400 years. 
E)  It was the nearest supernova detected in nearly 400 years. 
A)  It occurred only a few dozen light-years from Earth. 
B)  It provided the first observational evidence that supernovae actually occur. 
C)  It provided the first evidence that neutron stars exist. 
D)  It was the first supernova detected in nearly 400 years. 
E)  It was the nearest supernova detected in nearly 400 years.

At the end of its life, the remaining core of this star will be left behind as

The helium fusion process works by fusing two helium nuclei into one beryllium nucleus.

What is a planetary nebula?

What is the lifetime of a star of 0.1 solar masses and a luminosity of 0.01 that of the Sun. Assume the lifetime of the Sun is 10 billion years.

What is a helium flash?

There is no limit to the mass with which a star can be born.

Which type of star spends the shortest time as a main sequence star?

What will happen in the Sun immediately after it has exhausted its supply of hydrogen in its core?

According to this plot, which is the third most abundant element in the universe?

No stars are expected with masses greater than 150 times our Sun because

Which type of star spends the longest time as a protostar?

Carbon fusion occur in high-mass stars but not in low-mass stars because ________.

What is a planetary nebula?

What is the approximate range of masses that newborn main sequence stars can have?

What is a protostar?

Which element has the lowest mass per nuclear particle and therefore cannot release energy by either fusion or fission?

What happens when the gravity of a massive star is able to overcome neutron degeneracy pressure?

Which star has the shortest lifetime?

Why is Supernova 1987A particularly important to astronomers?

Our Place in the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundation of Modern Cosmology

Dark Matter, Dark Energy, and the Fate of the Universe

The Beginning of Time

Life in the Universe

Filters

Exam 12: Star Stuff

At the end of its life, the remaining core of this star will be left behind as

The helium fusion process works by fusing two helium nuclei into one beryllium nucleus.

What is a planetary nebula?

What is the lifetime of a star of 0.1 solar masses and a luminosity of 0.01 that of the Sun. Assume the lifetime of the Sun is 10 billion years.

What is a helium flash?

There is no limit to the mass with which a star can be born.

Which type of star spends the shortest time as a main sequence star?

What will happen in the Sun immediately after it has exhausted its supply of hydrogen in its core?

According to this plot, which is the third most abundant element in the universe?

No stars are expected with masses greater than 150 times our Sun because

Which type of star spends the longest time as a protostar?

Carbon fusion occur in high-mass stars but not in low-mass stars because ________.

What is a planetary nebula?

What is the approximate range of masses that newborn main sequence stars can have?

What is a protostar?

Which element has the lowest mass per nuclear particle and therefore cannot release energy by either fusion or fission?

What happens when the gravity of a massive star is able to overcome neutron degeneracy pressure?

Which star has the shortest lifetime?

Why is Supernova 1987A particularly important to astronomers?

Our Place in the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundation of Modern Cosmology

Dark Matter, Dark Energy, and the Fate of the Universe

The Beginning of Time

Life in the Universe

Filters