Question 1

The magnitude of a star depends on its luminosity and distance from us.

Accepted Answer

The answer of The magnitude of a star depends on...

Question 2

What role does helium play in spectral classification?

Accepted Answer

It is ionized in the hottest O...

Question 3

A parsec is about 3.3 light- years.

Accepted Answer

A) True 
 B)False

Question 4

Ionized helium lines are found in both type B and O stars.

Accepted Answer

A) True 
 B)False

Question 5

Why is hydrogen less obvious in B stars than in A class?

Accepted Answer

Above 10,000K, the h...

Question 6

Only A type stars show hydrogen lines in their spectra.

Accepted Answer

A) True 
 B)False

Question 7

The absolute magnitude scale is defined so that a difference of five magnitudes is a luminosity difference of _ .

Accepted Answer

100X, or a...

Question 8

Rigel has an apparent magnitude of + 0.18 and Betelgeuse an apparent magnitude of +0.45. What can you conclude from this?

Accepted Answer

A)   Rigel is brighter than Betelgeuse.
B)   Betelgeuse must be closer to Earth.
C)   Betelgeuse is brighter than Rigel.
D)   Rigel must be closer to Earth.
E)   Both stars are brighter than the full moon.F) A) and E)
G) B) and C)

Question 9

A +6.0 magnitude star is brighter than a +3.0 magnitude star.

Accepted Answer

A) True 
 B)False

Question 10

Almost all stars on the main sequence range from 1 to 10 solar luminosities.

Accepted Answer

A) True 
 B)False

Question 11

On a night when a human eye can see a fourth magnitude star, a 60mm telescope, with 100× the surface area as our pupil, would be able to just barely detect

Accepted Answer

A)   eleventh magnitude Tethys, Saturn's second largest moon.
B)   seventh magnitude Titan, Saturn's largest moon.
C)   ninth magnitude Barnard's Star.
D)   eighth magnitude Uranus.
E)   thirteenth magnitude Pluto.F) A) and D)
G) C) and D)

Question 12

The main difference between an A2V and F2V star is their .

Accepted Answer

temperatur...

Question 13

A star with an apparent magnitude of +2.3 and an absolute magnitude of +5.9 lies than 10 parsecs away.

Accepted Answer

The answer of A star with an apparent magnitude of...

Question 14

A parsec is slightly more than 200,000 AU.

Accepted Answer

A) True 
 B)False

Question 15

How did the Hipparcos mission revolutionize our knowledge of stellar properties?

Accepted Answer

In space, it had far better resolution t...

Question 16

White dwarfs like Sirius B are typically the size of _ .

Accepted Answer

The answer of White dwarfs like Sirius B are typically...

Question 17

In general, what can be said about type O and B stars compared to type K and M stars?

Accepted Answer

A)   They are hotter and younger.
B)   They are cooler and older.
C)   They are hotter and older.
D)   They are cooler and younger.
E)   They are neither hotter nor cooler, younger nor older.F) B) and D)
G) All of the above

Question 18

If Vega is apparent magnitude zero, and Deneb first magnitude, then

Accepted Answer

A)   Vega must be 2.5× hotter than Deneb.
B)   Deneb must be a main sequence star, and Vega a giant.
C)   Vega is about 100× brighter than Deneb.
D)   Deneb is one magnitude brighter than Vega.
E)   Vega is 2.5× brighter than Deneb.F) B) and C)
G) A) and C)

Question 19

What special type of information is yielded only by eclipsing binary stars?

Accepted Answer

The analysis of the light curve of eclip...

Question 20

What information can be gained from the light curves of eclipsing binaries?

Accepted Answer

A)   their masses
B)   their luminosities
C)   their sizes
D)   their distances
E)   their temperaturesF) A) and B)
G) A) and C)

Exam 11: Measuring the Stars: Giants, Dwarfs, and the Main Sequence

On a night when a human eye can see a fourth magnitude star, a 60mm telescope, with 100× the surface area as our pupil, would be able to just barely detect

Correct AnswerverifiedShow Answer

Rigel has an apparent magnitude of + 0.18 and Betelgeuse an apparent magnitude of +0.45. What can you conclude from this?

Correct AnswerverifiedShow Answer

A +6.0 magnitude star is brighter than a +3.0 magnitude star.

Correct AnswerverifiedShow Answer

The magnitude of a star depends on its luminosity and distance from us.

Correct AnswerverifiedShow Answer

What role does helium play in spectral classification?

Correct AnswerverifiedIt is ionized in the hottest O...View AnswerShow Answer

A parsec is about 3.3 light- years.

Correct AnswerverifiedShow Answer

If Vega is apparent magnitude zero, and Deneb first magnitude, then

Correct AnswerverifiedShow Answer

Almost all stars on the main sequence range from 1 to 10 solar luminosities.

Correct AnswerverifiedShow Answer

Why is hydrogen less obvious in B stars than in A class?

Correct AnswerverifiedAbove 10,000K, the h...View AnswerShow Answer

The main difference between an A2V and F2V star is their .

Correct Answerverifiedtemperatur...View AnswerShow Answer

How did the Hipparcos mission revolutionize our knowledge of stellar properties?

Correct AnswerverifiedIn space, it had far better resolution t...View AnswerShow Answer

The absolute magnitude scale is defined so that a difference of five magnitudes is a luminosity difference of _ .

Correct Answerverified100X, or a...View AnswerShow Answer

Only A type stars show hydrogen lines in their spectra.

Correct AnswerverifiedShow Answer

A star with an apparent magnitude of +2.3 and an absolute magnitude of +5.9 lies than 10 parsecs away.

Correct AnswerverifiedShow Answer

In general, what can be said about type O and B stars compared to type K and M stars?

Correct AnswerverifiedShow Answer

White dwarfs like Sirius B are typically the size of _ .

Correct AnswerverifiedShow Answer

A parsec is slightly more than 200,000 AU.

Correct AnswerverifiedShow Answer

What information can be gained from the light curves of eclipsing binaries?

Correct AnswerverifiedShow Answer

Ionized helium lines are found in both type B and O stars.

Correct AnswerverifiedShow Answer

What special type of information is yielded only by eclipsing binary stars?

Correct AnswerverifiedThe analysis of the light curve of eclip...View AnswerShow Answer

Correct Answer
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It is ionized in the hottest O...
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Above 10,000K, the h...
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temperatur...
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In space, it had far better resolution t...
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Correct Answer
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100X, or a...
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verified

Correct Answer
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The analysis of the light curve of eclip...
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