Question 1

While on the main sequence, what is a star's primary energy source?

Accepted Answer

A)  nuclear fusion 
B)  nuclear fission 
C)  gravitational potential energy 
D)  magnetic fields 
A)  nuclear fusion 
B)  nuclear fission 
C)  gravitational potential energy 
D)  magnetic fields

Question 2

What is the approximate mass of the lowest mass object that can initiate the nuclear fusion of hydrogen?

Accepted Answer

A)  0.08 solar mass 
B)  1 solar mass 
C)  8 solar masses 
D)  80 solar masses 
A)  0.08 solar mass 
B)  1 solar mass 
C)  8 solar masses 
D)  80 solar masses

Question 3

What occurs when some of the material collapsing to form a protostar is ejected from its poles?

Accepted Answer

A)  A protoplanetary disk forms. 
B)  The star stops collapsing. 
C)  The T Tauri phenomenon occurs. 
D)  Jets extend into the interstellar medium. 
A)  A protoplanetary disk forms. 
B)  The star stops collapsing. 
C)  The T Tauri phenomenon occurs. 
D)  Jets extend into the interstellar medium.

Question 4

Why does the main sequence have a limit at the lower end?

Accepted Answer

A)  Low mass stars form from the interstellar medium very rarely. 
B)  Low mass objects are composed primarily of solids, not gases. 
C)  The lower limit represents a star with zero radius. 
D)  A minimum temperature is required for hydrogen nuclear fusion to take place. 
A)  Low mass stars form from the interstellar medium very rarely. 
B)  Low mass objects are composed primarily of solids, not gases. 
C)  The lower limit represents a star with zero radius. 
D)  A minimum temperature is required for hydrogen nuclear fusion to take place.

Question 5

Protostars are generally smaller than main sequence stars.

Accepted Answer

A) True 
 B)False

While on the main sequence, what is a star's primary energy source?

What is the approximate mass of the lowest mass object that can initiate the nuclear fusion of hydrogen?

What occurs when some of the material collapsing to form a protostar is ejected from its poles?

Why does the main sequence have a limit at the lower end?

Protostars are generally smaller than main sequence stars.

The Scale of the Cosmos: Space and Time

Users Guide to the Sky: Patterns and Cycles

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments: Extending Humanitys Vision

The Sun: the Closest Star

The Family of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

Planet Formation and Exoplanets

Comparative Planetology of the Terrestrial Planets

The Outer Solar System

Life on Other Worlds

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Exam 7: The Structure and Formation of Stars

While on the main sequence, what is a star's primary energy source?

What is the approximate mass of the lowest mass object that can initiate the nuclear fusion of hydrogen?

What occurs when some of the material collapsing to form a protostar is ejected from its poles?

Why does the main sequence have a limit at the lower end?

Protostars are generally smaller than main sequence stars.

The Scale of the Cosmos: Space and Time

Users Guide to the Sky: Patterns and Cycles

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments: Extending Humanitys Vision

The Sun: the Closest Star

The Family of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

Planet Formation and Exoplanets

Comparative Planetology of the Terrestrial Planets

The Outer Solar System

Life on Other Worlds

Filters