Question 1

Which of the following nuclei can a compact astronomical object with a mass of 0.05 MSun create through fusion?

Accepted Answer

A)  none 
B)  deuterium 
C)  helium 
D)  carbon 
A)  none 
B)  deuterium 
C)  helium 
D)  carbon

Question 2

What are two reasons that molecules are so abundant within giant molecular clouds?

Accepted Answer

The high densities enable them

Question 3

Why does the initial mass function of stars differ from the actual distribution of stars in the Milky Way at the present day?

Accepted Answer

The initial mass function describes the

Question 4

How might an astronomer measure the initial mass function?

Accepted Answer

A)  catalog the masses of all the stars in the Milky Way 
B)  catalog the masses of all nearby galaxies 
C)  catalog the masses of all the molecular clouds in the Milky Way 
D)  catalog the masses of all the stars in a young open cluster 
A)  catalog the masses of all the stars in the Milky Way 
B)  catalog the masses of all nearby galaxies 
C)  catalog the masses of all the molecular clouds in the Milky Way 
D)  catalog the masses of all the stars in a young open cluster

Question 5

In what wavelength range do protostars emit most of their energy?

Accepted Answer

A)  optical 
B)  radio 
C)  infrared 
D)  ultraviolet 
A)  optical 
B)  radio 
C)  infrared 
D)  ultraviolet

Question 6

What would happen to the Milky Way's interstellar medium if more supernovae occurred than usual?

Accepted Answer

It would b

Question 7

Massive stars on the main sequence generate energy through the:

Accepted Answer

A)  proton-proton chain. 
B)  CNO cycle. 
C)  triple alpha reaction. 
D)  onion model. 
A)  proton-proton chain. 
B)  CNO cycle. 
C)  triple alpha reaction. 
D)  onion model.

Question 8

Which of the following is most strongly affected by interstellar dust?

Accepted Answer

A)  infrared light 
B)  visible light 
C)  microwaves 
D)  radio waves 
A)  infrared light 
B)  visible light 
C)  microwaves 
D)  radio waves

Question 9

What is the wavelength of radiation produced by the system in the figure below?

Accepted Answer

A)  91 nm 
B)  121 nm 
C)  656 nm 
D)  21 cm 
A)  91 nm 
B)  121 nm 
C)  656 nm 
D)  21 cm

Question 10

Which of the following is an important effect of interstellar dust?

Accepted Answer

A)  a platform for the formation of molecules 
B)  pressure equilibrium in the interstellar medium 
C)  a source of diagnostic emission lines 
D)  heating of the interstellar medium 
A)  a platform for the formation of molecules 
B)  pressure equilibrium in the interstellar medium 
C)  a source of diagnostic emission lines 
D)  heating of the interstellar medium

Question 11

A protostar becomes a star when:

Accepted Answer

A)  its luminosity reaches a maximum. 
B)  its surface temperature reaches 5,000 K. 
C)  it loses all its gravitational energy. 
D)  nuclear fusion begins. 
A)  its luminosity reaches a maximum. 
B)  its surface temperature reaches 5,000 K. 
C)  it loses all its gravitational energy. 
D)  nuclear fusion begins.

Question 12

A Herbig-Haro object is moving at 100 km/s and lies 10 parsecs from a protostar.What is a lower limit for the lifetime of the protostar? Express your answer in years.

Accepted Answer

The answer of A Herbig-Haro object is moving at 100...

Question 13

What is the typical size of an interstellar dust grain?

Accepted Answer

A)  50 microns 
B)  5 microns 
C)  5 nm 
D)  500 nm 
A)  50 microns 
B)  5 microns 
C)  5 nm 
D)  500 nm

Question 14

Why do massive stars use the CNO cycle to generate energy,rather than the proton-proton chain?

Accepted Answer

A)  It is more temperature sensitive. 
B)  Massive stars have more carbon. 
C)  It produces more energy per helium nucleus. 
D)  It uses up the carbon too quickly in low-mass stars. 
A)  It is more temperature sensitive. 
B)  Massive stars have more carbon. 
C)  It produces more energy per helium nucleus. 
D)  It uses up the carbon too quickly in low-mass stars.

Question 15

An interstellar gas cloud with a density of 100 particles per cubic centimeter and with a temperature of 100 K is in equilibrium with a medium with a density of 0.1 particles per cubic centimeter and 10⁶ K.What is the most likely explanation?

Accepted Answer

A)  supernova blast waves 
B)  photoionization 
C)  turbulence 
D)  the ideal gas law 
A)  supernova blast waves 
B)  photoionization 
C)  turbulence 
D)  the ideal gas law

Question 16

Suppose a star forms with 10 times the mass of the Sun and without any elements heavier than helium.How will the central temperature of this star compare to a star with the same mass but the same composition as the Sun?

Accepted Answer

The metal-free star will be ho

Question 17

A brown dwarf is a:

Accepted Answer

A)  low-mass star. 
B)  failed star. 
C)  stellar remnant supported by electron degeneracy pressure. 
D)  stellar remnant supported by neutron degeneracy pressure. 
A)  low-mass star. 
B)  failed star. 
C)  stellar remnant supported by electron degeneracy pressure. 
D)  stellar remnant supported by neutron degeneracy pressure.

Question 18

List the five phases of the interstellar medium in order from coolest to hottest.

Accepted Answer

Molecular clouds,H I

Question 19

Which of the following provides the best example of turbulence?

Accepted Answer

A)  a molecular cloud with large whorls containing many smaller whorls 
B)  a jet launched at near the speed of light by a supermassive black hole 
C)  a large network of convection cells inside a star 
D)  an accretion disk rotating around a black hole 
A)  a molecular cloud with large whorls containing many smaller whorls 
B)  a jet launched at near the speed of light by a supermassive black hole 
C)  a large network of convection cells inside a star 
D)  an accretion disk rotating around a black hole

Question 20

What does it mean for a giant molecular cloud to have a hierarchy of structures?

Accepted Answer

The cloud has smalle

Which of the following nuclei can a compact astronomical object with a mass of 0.05 M_Sun create through fusion?

What are two reasons that molecules are so abundant within giant molecular clouds?

Why does the initial mass function of stars differ from the actual distribution of stars in the Milky Way at the present day?

How might an astronomer measure the initial mass function?

In what wavelength range do protostars emit most of their energy?

What would happen to the Milky Way's interstellar medium if more supernovae occurred than usual?

Massive stars on the main sequence generate energy through the:

Which of the following is most strongly affected by interstellar dust?

What is the wavelength of radiation produced by the system in the figure below?

Which of the following is an important effect of interstellar dust?

A protostar becomes a star when:

A Herbig-Haro object is moving at 100 km/s and lies 10 parsecs from a protostar.What is a lower limit for the lifetime of the protostar? Express your answer in years.

What is the typical size of an interstellar dust grain?

Why do massive stars use the CNO cycle to generate energy,rather than the proton-proton chain?

An interstellar gas cloud with a density of 100 particles per cubic centimeter and with a temperature of 100 K is in equilibrium with a medium with a density of 0.1 particles per cubic centimeter and 10⁶ K.What is the most likely explanation?

Suppose a star forms with 10 times the mass of the Sun and without any elements heavier than helium.How will the central temperature of this star compare to a star with the same mass but the same composition as the Sun?

A brown dwarf is a:

List the five phases of the interstellar medium in order from coolest to hottest.

Which of the following provides the best example of turbulence?

What does it mean for a giant molecular cloud to have a hierarchy of structures?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters

Exam 12: Nursery of the Stars: the Interstellar Medium and Star Formation

Which of the following nuclei can a compact astronomical object with a mass of 0.05 MSun create through fusion?

What are two reasons that molecules are so abundant within giant molecular clouds?

Why does the initial mass function of stars differ from the actual distribution of stars in the Milky Way at the present day?

How might an astronomer measure the initial mass function?

In what wavelength range do protostars emit most of their energy?

What would happen to the Milky Way's interstellar medium if more supernovae occurred than usual?

Massive stars on the main sequence generate energy through the:

Which of the following is most strongly affected by interstellar dust?

What is the wavelength of radiation produced by the system in the figure below?

Which of the following is an important effect of interstellar dust?

A protostar becomes a star when:

A Herbig-Haro object is moving at 100 km/s and lies 10 parsecs from a protostar.What is a lower limit for the lifetime of the protostar? Express your answer in years.

What is the typical size of an interstellar dust grain?

Why do massive stars use the CNO cycle to generate energy,rather than the proton-proton chain?

An interstellar gas cloud with a density of 100 particles per cubic centimeter and with a temperature of 100 K is in equilibrium with a medium with a density of 0.1 particles per cubic centimeter and 10⁶ K.What is the most likely explanation?

Suppose a star forms with 10 times the mass of the Sun and without any elements heavier than helium.How will the central temperature of this star compare to a star with the same mass but the same composition as the Sun?

A brown dwarf is a:

List the five phases of the interstellar medium in order from coolest to hottest.

Which of the following provides the best example of turbulence?

What does it mean for a giant molecular cloud to have a hierarchy of structures?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters

Which of the following nuclei can a compact astronomical object with a mass of 0.05 M_Sun create through fusion?