Question 1

We can identify only a small fraction of all the pulsars that exist in our galaxy because:

Accepted Answer

A)  gas and dust efficiently block radio photons 
B)  few swing their beam of synchrotron emission in our direction 
C)  most have evolved to become black holes,which emit no light 
D)  massive stars are very rare 
A)  gas and dust efficiently block radio photons 
B)  few swing their beam of synchrotron emission in our direction 
C)  most have evolved to become black holes,which emit no light 
D)  massive stars are very rare

Question 2

If a 25 M$\bigodot$ main-sequence star loses mass at a rate of 10-6 M$\bigodot$/yr then how much mass will it lose in its 3-million-year lifetime?

Accepted Answer

A)  3 M$\bigodot$ 
B)  5 M$\bigodot$ 
C)  8 M$\bigodot$ 
D)  12 M$\bigodot$ 
A)  3 M$\bigodot$ 
B)  5 M$\bigodot$ 
C)  8 M$\bigodot$ 
D)  12 M$\bigodot$

Question 3

Pulsating variable stars are more commonly known as pulsars.

Accepted Answer

A) True 
 B)False

Question 4

If an 8 M$\bigodot$ star loses mass at an average rate of 10-6 M$\bigodot$/yr in a stellar wind,how many years would it take for its mass to be reduced to 6 M$\bigodot$? Would this amount of mass loss be possible in the star's lifetime?

Accepted Answer

If R is the mass loss rate and

Question 5

The figure below shows the relative abundances of different elements on Earth.Explain why elements less massive than iron are,in general,most common,why there is a small peak at Iron,and why elements more massive than iron are less common.

Accepted Answer

Elements less massive than iron are comm

Question 6

Examine the figure of a pulsar below.What are pulsars,and what circumstance must the Earth be in for astronomers to observe one?

Accepted Answer

Pulsars are neutron stars that

Question 7

High-mass stars differ from low-mass stars in that they burn helium to carbon when on the main sequence.

Accepted Answer

A) True 
 B)False

Question 8

An 8 M$\bigodot$ star will eventually die as a Type Ia supernova.

Accepted Answer

A) True 
 B)False

Question 9

Which of the stars from the figure below would show variability in its brightness?

Accepted Answer

A)  Star A 
B)  Star B 
C)  Star C 
D)  Star D 
A)  Star A 
B)  Star B 
C)  Star C 
D)  Star D

Question 10

The collapse of the core of a high-mass star at the end of its life lasts approximately:

Accepted Answer

A)  one second 
B)  one hour 
C)  one week 
D)  one year 
A)  one second 
B)  one hour 
C)  one week 
D)  one year

Question 11

In comparison,the main-sequence lifetime of the star is just less than 81 million years (Table 12.1).Therefore,the star could lose this much mass because its main-sequence lifetime is much longer than the time it would take to do so.

-Name at least two processes that speed the collapse of the core of a dying high-mass star.

Accepted Answer

The answer should include at least two o

We can identify only a small fraction of all the pulsars that exist in our galaxy because:

If a 25 M_$\bigodot$ main-sequence star loses mass at a rate of 10^-6 M_$\bigodot$/yr then how much mass will it lose in its 3-million-year lifetime?

Pulsating variable stars are more commonly known as pulsars.

If an 8 M_$\bigodot$ star loses mass at an average rate of 10^-6 M_$\bigodot$/yr in a stellar wind,how many years would it take for its mass to be reduced to 6 M_$\bigodot$? Would this amount of mass loss be possible in the star's lifetime?

The figure below shows the relative abundances of different elements on Earth.Explain why elements less massive than iron are,in general,most common,why there is a small peak at Iron,and why elements more massive than iron are less common.

Examine the figure of a pulsar below.What are pulsars,and what circumstance must the Earth be in for astronomers to observe one?

High-mass stars differ from low-mass stars in that they burn helium to carbon when on the main sequence.

An 8 M_$\bigodot$ star will eventually die as a Type Ia supernova.

Which of the stars from the figure below would show variability in its brightness?

The collapse of the core of a high-mass star at the end of its life lasts approximately:

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: The Sun

Evolution of Low-Mass Stars

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

Filters

Exam 13: Evolution of High-Mass Stars

We can identify only a small fraction of all the pulsars that exist in our galaxy because:

If a 25 M ⨀\bigodot⨀ main-sequence star loses mass at a rate of 10-6 M ⨀\bigodot⨀ /yr then how much mass will it lose in its 3-million-year lifetime?

Pulsating variable stars are more commonly known as pulsars.

If an 8 M ⨀\bigodot⨀ star loses mass at an average rate of 10-6 M ⨀\bigodot⨀ /yr in a stellar wind,how many years would it take for its mass to be reduced to 6 M ⨀\bigodot⨀ ? Would this amount of mass loss be possible in the star's lifetime?

The figure below shows the relative abundances of different elements on Earth.Explain why elements less massive than iron are,in general,most common,why there is a small peak at Iron,and why elements more massive than iron are less common.

Examine the figure of a pulsar below.What are pulsars,and what circumstance must the Earth be in for astronomers to observe one?

High-mass stars differ from low-mass stars in that they burn helium to carbon when on the main sequence.

An 8 M ⨀\bigodot⨀ star will eventually die as a Type Ia supernova.

Which of the stars from the figure below would show variability in its brightness?

The collapse of the core of a high-mass star at the end of its life lasts approximately:

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: The Sun

Evolution of Low-Mass Stars

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

Filters

If a 25 M_$\bigodot$ main-sequence star loses mass at a rate of 10^-6 M_$\bigodot$/yr then how much mass will it lose in its 3-million-year lifetime?

If an 8 M_$\bigodot$ star loses mass at an average rate of 10^-6 M_$\bigodot$/yr in a stellar wind,how many years would it take for its mass to be reduced to 6 M_$\bigodot$? Would this amount of mass loss be possible in the star's lifetime?

An 8 M_$\bigodot$ star will eventually die as a Type Ia supernova.