Question 1

In which spectral sequence are the hottest stars categorized?

Accepted Answer

A)   O stars
B)   B stars
C)   A stars
D)   F stars
E)   K starsF) D) and E)
G) A) and E)

Question 2

Any star that is more luminous than the Sun, but has the same temperature as the Sun, is a(n)  ____.

Accepted Answer

A)   pulsating star
B)   white dwarf
C)   zero-age main-sequence star
D)   giant
E)   brown dwarfF) A) and B)
G) C) and D) D

Question 3

Figure 9-1 
In the accompanying figure (Figure 9-1) , which region represents supergiant stars? Note: (C) represents the entire main sequence while (D) and (E) represent only small parts of the main sequence.

Accepted Answer

The answer of  
Figure 9-1 
In the accompanying figure...

Question 4

A star has a parallax angle of 0.019 seconds of arc.  How far away is this star from Earth?

Accepted Answer

The answer of A star has a parallax angle of...

Question 5

The most common stars are _______________ stars.

Accepted Answer

lower-main...

Question 6

List the three types of binary stars.

Accepted Answer

visual binary, spect...

Question 7

The luminosity class is assigned to a star by studying the absorption lines in the spectrum of the star.

Accepted Answer

A) True 
 B)False

Question 8

Figure 9-1 
In the accompanying figure (Figure 9-1) , which region represents stars that are extremely bright and emit most of their radiation as ultraviolet light? Note: (C) represents the entire main sequence while (D) and (E) represent only small parts of the main sequence.

Accepted Answer

D

Question 9

Hydrogen lines are weak in the spectra of hot O-type stars because ____.

Accepted Answer

A)   most of the hydrogen has been converted to helium
B)   a good spectrum of these stars is difficult to obtain
C)   these stars have no atmosphere
D)   gravitational pressure pushes all the hydrogen lines out of the visible spectrum
E)   most of the hydrogen is ionized to high energy levelsF) B) and C)
G) A) and C)

Question 10

Figure 9-1
The horizontal axis in the accompanying figure (Figure 9-1)  is labeled _____.

Accepted Answer

A)   temperature
B)   radius
C)   apparent magnitude
D)   absolute magnitude
E)   luminosityF) C) and E)
G) C) and D) A

Question 11

Explain why the current spectral classification letters are all jumbled and not in alphabetical order.

Accepted Answer

The spectral classification sequence ori...

Question 12

The Balmer thermometer works because the strength of the Balmer lines depends on the _________ of the star's surface.

Accepted Answer

A)   emissivity
B)   temperature
C)   area
D)   granulation
E)   spectraF) None of the above
G) C) and D)

Question 13

The Balmer series of hydrogen absorption lines in stars is located in what part of the electromagnetic spectrum?

Accepted Answer

A)   gamma ray region
B)   ultraviolet region
C)   visible region
D)   infrared region
E)   microwave regionF) A) and C)
G) All of the above

Question 14

If a star has an apparent magnitude of +5 and an absolute magnitude of -10, what can we say about that star?

Accepted Answer

A)   The star is farther than 10 parsecs away.
B)   The star is closer than 10 parsecs away.
C)   The star has a very large chromosphere.
D)   The star has a very large corona.
E)   The star is fainter than the Sun.F) All of the above
G) C) and D)

Question 15

The most accurate way to determine the surface temperature of a star is to study the pattern of emission lines from various atoms.

Accepted Answer

A) True 
 B)False

Question 16

Figure 9-1
The vertical axis in the accompanying figure (Figure 9-1)  is labeled _____.

Accepted Answer

A)   temperature
B)   radius
C)   apparent visual magnitude
D)   absolute visual magnitude
E)   massF) D) and E)
G) A) and B)

Question 17

A star's absolute visual magnitude depends only on the star's ______ and _____.

Accepted Answer

A)   temperature; mass
B)   diameter; mass
C)   temperature; density
D)   diameter; density
E)   distance; magnitudeF) A) and B)
G) B) and D)

Question 18

Briefly state or explain the mass-luminosity relation for stars.

Accepted Answer

The luminosity of a star is di...

Question 19

Which star has the highest density (mass per unit volume) ?

Accepted Answer

A)   white dwarf
B)   main sequence
C)   supergiant
D)   red giant
E)   regular giantF) C) and D)
G) C) and E)

Question 20

A star's absolute visual magnitude depends on its _______________ and _______________.

Accepted Answer

temperatur...

Exam 9: The Family of Stars

In which spectral sequence are the hottest stars categorized?

Correct AnswerverifiedShow Answer

Any star that is more luminous than the Sun, but has the same temperature as the Sun, is a(n) ____.

Correct AnswerverifiedD

Figure 9-1 In the accompanying figure (Figure 9-1) , which region represents supergiant stars? Note: (C) represents the entire main sequence while (D) and (E) represent only small parts of the main sequence.

Correct AnswerverifiedShow Answer

A star has a parallax angle of 0.019 seconds of arc. How far away is this star from Earth?

Correct AnswerverifiedShow Answer

The most common stars are _______________ stars.

Correct Answerverifiedlower-main...View AnswerShow Answer

List the three types of binary stars.

Correct Answerverifiedvisual binary, spect...View AnswerShow Answer

The luminosity class is assigned to a star by studying the absorption lines in the spectrum of the star.

Correct AnswerverifiedShow Answer

Figure 9-1 In the accompanying figure (Figure 9-1) , which region represents stars that are extremely bright and emit most of their radiation as ultraviolet light? Note: (C) represents the entire main sequence while (D) and (E) represent only small parts of the main sequence.

Correct AnswerverifiedD

Hydrogen lines are weak in the spectra of hot O-type stars because ____.

Correct AnswerverifiedShow Answer

Figure 9-1 The horizontal axis in the accompanying figure (Figure 9-1) is labeled _____.

Correct AnswerverifiedA

Explain why the current spectral classification letters are all jumbled and not in alphabetical order.

Correct AnswerverifiedThe spectral classification sequence ori...View AnswerShow Answer

The Balmer thermometer works because the strength of the Balmer lines depends on the _________ of the star's surface.

Correct AnswerverifiedShow Answer

The Balmer series of hydrogen absorption lines in stars is located in what part of the electromagnetic spectrum?

Correct AnswerverifiedShow Answer

If a star has an apparent magnitude of +5 and an absolute magnitude of -10, what can we say about that star?

Correct AnswerverifiedShow Answer

The most accurate way to determine the surface temperature of a star is to study the pattern of emission lines from various atoms.

Correct AnswerverifiedShow Answer

Figure 9-1 The vertical axis in the accompanying figure (Figure 9-1) is labeled _____.

Correct AnswerverifiedShow Answer

A star's absolute visual magnitude depends only on the star's ______ and _____.

Correct AnswerverifiedShow Answer

Briefly state or explain the mass-luminosity relation for stars.

Correct AnswerverifiedThe luminosity of a star is di...View AnswerShow Answer

Which star has the highest density (mass per unit volume) ?

Correct AnswerverifiedShow Answer

A star's absolute visual magnitude depends on its _______________ and _______________.

Correct Answerverifiedtemperatur...View AnswerShow Answer

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D

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lower-main...
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visual binary, spect...
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D

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A

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The spectral classification sequence ori...
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A star's absolute visual magnitude depends only on the star's __ and _.

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The luminosity of a star is di...
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A star's absolute visual magnitude depends on its _ and _.

Correct Answer
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temperatur...
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