Question 1

You discover a binary star system in which one star is a 15 MSᵤn main-sequence star and the other is a 10 MSᵤn giant.How do we think that a star system such as this might have come to exist?

Accepted Answer

A)  The giant must once have been the more massive star,but is now less massive because it transferred some of its mass to its companion.
B)  Although both stars probably formed from the same clump of gas,the more massive one must have had its birth slowed so that it became a main-sequence stars millions of years later than its less massive companion.
C)  The two stars probably were once separate,but became a binary when a close encounter allowed their mutual gravity to pull them together.
D)  The two stars are simply evolving normally and independently,and one has become a giant before the other.

Question 2

Which of the following observations would not be likely to provide information about the final,explosive stages of a star's life?

Accepted Answer

A)  studying the light rings around Supernova 1987A in the Large Magellanic Cloud
B)  decades of continuous monitoring of red giants in a globular cluster
C)  observing the structures of planetary nebulae
D)  neutrino detections from nearby supernovae

Question 3

An H-R diagram for a globular cluster will show a horizontal branch-a line of stars above the main-sequence but to the left of the subgiants and red giants.Which of the following statements about these horizontal branch stars is true?

Accepted Answer

A)  They have inert (non-burning) carbon cores.
B)  Their sole source of energy is hydrogen shell burning.
C)  They generate energy through both hydrogen fusion and helium fusion.
D)  In a particular star cluster,all horizontal branch stars have the same spectral type.

Question 4

Which of the following statements about degeneracy pressure is not true?

Accepted Answer

A)  Degeneracy pressure varies with the temperature of the star.
B)  Degeneracy pressure can halt gravitational contraction of a star even when no fusion is occurring in the core.
C)  Degeneracy pressure keeps any protostar less than 0.08 solar mass from becoming a true,hydrogen-fusing star.
D)  Degeneracy pressure arises out of the ideas of quantum mechanics.
E)  Degeneracy pressure supports white dwarfs against gravity.

Question 5

What do astronomers mean when they say that we are all "star stuff"?

Accepted Answer

A)  that life would be impossible without energy from the Sun
B)  that Earth formed at the same time as the Sun
C)  that the carbon,oxygen,and many elements essential to life were created by nucleosynthesis in stellar cores
D)  that the Sun formed from the interstellar medium: the "stuff" between the stars
E)  that the Universe contains billions of stars

Question 6

Suppose that the star Betelgeuse (the upper left shoulder of Orion) were to supernova tomorrow (as seen here on Earth) .What would it look like to the naked eye?

Accepted Answer

A)  Betelgeuse would remain a dot of light,but would suddenly become so bright that,for a few weeks,we'd be able to see this dot in the daytime.
B)  We'd see a cloud of gas expanding away from the position where Betelgeuse used to be.Over a period of a few weeks,this cloud would fill our entire sky.
C)  Because the supernova destroys the star,Betelgeuse would suddenly disappear from view.
D)  Betelgeuse would suddenly appear to grow larger in size,soon reaching the size of the full Moon.It would also be about as bright as the full Moon.

Question 7

The following questions refer to the sketch below of an H-R diagram for a star cluster.
 
-Consider the star to which the arrow points.Which of the following statements about this star is not true?

Accepted Answer

A)  It is significantly less massive than the Sun.
B)  It is larger in radius than the Sun.
C)  It is brighter than the Sun.
D)  Its surface temperature is lower than the Sun's.
E)  Its core temperature is higher than the Sun's.

Question 8

The following questions refer to the H-R diagram below that shows the life track of a 1-solar-mass star,with various stages labeled with Roman numerals.
 
-During which stage does the star have an inert (nonburning) carbon core?

Accepted Answer

A)  ii
B)  iii
C)  iv
D)  vi
E)  viii

Question 9

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 evidence that supernovae really occur.
C)  It provided the first evidence that neutron stars really exist.
D)  It was the first supernova detected in nearly 400 years.
E)  It was the nearest supernova detected in nearly 400 years.

Question 10

Photographs of many young stars show long jets of material apparently being ejected from their poles.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following lists the stages of life for a low-mass star in the correct order?

Accepted Answer

A)  protostar,main-sequence star,red giant,planetary nebula,white dwarf
B)  protostar,main-sequence star,red giant,supernova,neutron star
C)  protostar,main-sequence star,planetary nebula,red giant
D)  main-sequence star,white dwarf,red giant,planetary nebula,protostar

Question 12

What can we learn about a star from a life track on an H-R diagram?

Accepted Answer

A)  how long ago it was born
B)  when it will die
C)  where it is located
D)  what surface temperature and luminosity it will have at each stage of its life
E)  all of the above

Question 13

Which of the following types of data provide evidence that helps us understand the life tracks of low-mass stars?

Accepted Answer

A)  H-R diagrams of open clusters
B)  observing a low-mass star over many years
C)  H-R diagrams of globular clusters
D)  spacecraft observations of the Sun

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

Convection never occurs in the core of any type of star.

Accepted Answer

A) True 
 B)False

Question 16

Which event marks the beginning of a supernova?

Accepted Answer

A)  the onset of helium burning after a helium flash in a star with mass comparable to that of the Sun
B)  the sudden outpouring of X-rays from a newly formed accretion disk
C)  the sudden collapse of an iron core into a compact ball of neutrons
D)  the beginning of neon burning in an extremely massive star
E)  the expansion of a low-mass star into a red giant

Question 17

This diagram represents the life track of a 1-solar-mass star.Refer to the life stages labeled with Roman numerals.
 
-During which stage does the star have an inert (non-burning) carbon core surrounded by shells of helium and hydrogen burning?

Accepted Answer

A)  II
B)  III
C)  VI
D)  VII
E)  VIII

Question 18

Do you think it is possible that a 1.5-solar-mass red giant could harbor an advanced civilization? Explain your reasoning.

Accepted Answer

A 1.5-solar-mass red giant is a temporar...

Question 19

Which of the following spectral types is more likely to be a flare star?

Accepted Answer

A)  KIII
B)  MV
C)  GV
D)  I
E)  BII

Question 20

Process of Science: How do observations of stars help us understand the theory of atomic nuclei?

Accepted Answer

Many nuclear reactions occur during the ...

Exam 17: Star Stuff

Which of the following observations would not be likely to provide information about the final,explosive stages of a star's life?

Correct AnswerverifiedShow Answer

An H-R diagram for a globular cluster will show a horizontal branch-a line of stars above the main-sequence but to the left of the subgiants and red giants.Which of the following statements about these horizontal branch stars is true?

Correct AnswerverifiedShow Answer

Why is Supernova 1987A particularly important to astronomers?

Correct AnswerverifiedShow Answer

What do astronomers mean when they say that we are all "star stuff"?

Correct AnswerverifiedShow Answer

Suppose that the star Betelgeuse (the upper left shoulder of Orion) were to supernova tomorrow (as seen here on Earth) .What would it look like to the naked eye?

Correct AnswerverifiedShow Answer

Convection never occurs in the core of any type of star.

Correct AnswerverifiedShow Answer

Do you think it is possible that a 1.5-solar-mass red giant could harbor an advanced civilization? Explain your reasoning.

Correct AnswerverifiedA 1.5-solar-mass red giant is a temporar...View AnswerShow Answer

Photographs of many young stars show long jets of material apparently being ejected from their poles.

Correct AnswerverifiedShow Answer

The following questions refer to the H-R diagram below that shows the life track of a 1-solar-mass star,with various stages labeled with Roman numerals. -During which stage does the star have an inert (nonburning) carbon core?

Correct AnswerverifiedShow Answer

You discover a binary star system in which one star is a 15 MSᵤn main-sequence star and the other is a 10 MSᵤn giant.How do we think that a star system such as this might have come to exist?

Correct AnswerverifiedShow Answer

What can we learn about a star from a life track on an H-R diagram?

Correct AnswerverifiedShow Answer

Which of the following types of data provide evidence that helps us understand the life tracks of low-mass stars?

Correct AnswerverifiedShow Answer

Which of the following lists the stages of life for a low-mass star in the correct order?

Correct AnswerverifiedShow Answer

Which of the following statements about degeneracy pressure is not true?

Correct AnswerverifiedShow Answer

The following questions refer to the sketch below of an H-R diagram for a star cluster. -Consider the star to which the arrow points.Which of the following statements about this star is not true?

Correct AnswerverifiedShow Answer

Which event marks the beginning of a supernova?

Correct AnswerverifiedShow Answer

Which of the following spectral types is more likely to be a flare star?

Correct AnswerverifiedShow Answer

Process of Science: How do observations of stars help us understand the theory of atomic nuclei?

Correct AnswerverifiedMany nuclear reactions occur during the ...View AnswerShow Answer

This diagram represents the life track of a 1-solar-mass star.Refer to the life stages labeled with Roman numerals. -During which stage does the star have an inert (non-burning) carbon core surrounded by shells of helium and hydrogen burning?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A 1.5-solar-mass red giant is a temporar...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Many nuclear reactions occur during the ...
View Answer

Correct Answer
verified

Correct Answer
verified