Question 1

A star of spectral type O lives approximately how long on the main sequence?

Accepted Answer

A) 1,000 years 
B) 10,000 years 
C) 10 million years 
D) 100 million years 
E) 1 billion years 
A) 1,000 years 
B) 10,000 years 
C) 10 million years 
D) 100 million years 
E) 1 billion years

Question 2

Which has a greater luminosity,a star with absolute magnitude +4 or a star with absolute magnitude -6? By how much is it brighter?

Accepted Answer

A star with absolute magnitude -6 is int

Question 3

The sketch below shows groups of stars on the H-R diagram labeled (a)through (e).Note that (a)represents the entire main sequence while (c)and (d)represent only small parts of the main sequence.
  
-Which group represents stars of the largest radii?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
E) E 
A) A 
B) B 
C) C 
D) D 
E) E

Question 4

Process of Science: Why is the classification of stellar spectral types not in alphabetical order?

Accepted Answer

Stars were first classified empirically,

Question 5

On a Hertzsprung-Russell diagram,where would we find stars that are cool and dim?

Accepted Answer

A) upper right 
B) lower right 
C) upper left 
D) lower left 
A) upper right 
B) lower right 
C) upper left 
D) lower left

Question 6

To calculate the masses of stars in a binary system,we must measure their

Accepted Answer

A) spectral types and distance from Earth. 
B) absolute magnitudes and luminosities. 
C) luminosities and distance from Earth. 
D) orbital period and average orbital distance. 
A) spectral types and distance from Earth. 
B) absolute magnitudes and luminosities. 
C) luminosities and distance from Earth. 
D) orbital period and average orbital distance.

Question 7

Which is brighter in our sky,a star with apparent magnitude 2 or a star with apparent magnitude 7? By how much is the star brighter?

Accepted Answer

A star with apparent magnitude 2 is 100

Question 8

Refer to the choices in the table for the following questions.
  
-Which star looks reddest in color?

Accepted Answer

The answer of Refer to the choices in the table...

Question 9

The spectral sequence in order of decreasing temperature is

Accepted Answer

A) OFBAGKM. 
B) OBAGFKM. 
C) OBAFGKM. 
D) ABFGKMO. 
E) BAGFKMO. 
A) OFBAGKM. 
B) OBAGFKM. 
C) OBAFGKM. 
D) ABFGKMO. 
E) BAGFKMO.

Question 10

Massive,more luminous stars have shorter lives than their smaller,dimmer counterparts.

Accepted Answer

A) True 
 B)False

Question 11

The following questions refer to the sketch of the H-R diagram below.Please choose the best answer in each case,i.e. ,choice (a)refers to the entire main sequence,while (c)and (d)refer to only small parts of the main sequence.If choice (c)or (d)offers a better answer to a particular question than (a),use the best choice.You may use the same choice more than once.
  
-Which group represents stars that have no nuclear fusion in their cores?

Accepted Answer

The answer of The following questions refer to the sketch...

Question 12

Two stars,Fred and Barney,are of the same size.Fred has spectral type F,while Barney has spectral type B.Which one is more luminous?

Accepted Answer

Barney has a hotter surface te

Question 13

Some stars are cool enough to have molecules in their atmosphere.

Accepted Answer

A) True 
 B)False

Question 14

Two stars,Tom and Jerry,have the same spectral type.Tom is luminosity class V and Jerry is luminosity class I.Which star is bigger? Which star is more luminous? Which star has a hotter surface temperature? Explain your answers.

Accepted Answer

Tom is on the main sequence,while Jerry

Question 15

What is the approximate chemical composition (by mass)with which all stars are born?

Accepted Answer

A) three quarters hydrogen,one quarter helium,no more than 2% heavier elements 
B) half hydrogen and half helium 
C) 98% hydrogen,2% helium 
D) 95% hydrogen,4% helium,no more than 1% heavier elements 
A) three quarters hydrogen,one quarter helium,no more than 2% heavier elements 
B) half hydrogen and half helium 
C) 98% hydrogen,2% helium 
D) 95% hydrogen,4% helium,no more than 1% heavier elements

Question 16

The total amount of power (in watts,for example)that a star radiates into space is called its

Accepted Answer

A) apparent brightness. 
B) absolute magnitude. 
C) luminosity. 
D) flux. 
A) apparent brightness. 
B) absolute magnitude. 
C) luminosity. 
D) flux.

Question 17

Which of the following statements about spectral types of stars is not generally true?

Accepted Answer

A) The spectral type of a star can be used to determine its surface temperature. 
B) The spectral type of a star can be used to determine its distance. 
C) The spectral type of a star can be used to determine its color. 
D) The spectral type of a star can be determined by identifying lines in its spectrum. 
A) The spectral type of a star can be used to determine its surface temperature. 
B) The spectral type of a star can be used to determine its distance. 
C) The spectral type of a star can be used to determine its color. 
D) The spectral type of a star can be determined by identifying lines in its spectrum.

Question 18

What is the common trait of all main-sequence stars?

Accepted Answer

A) They are in the final stage of their lives. 
B) They generate energy through hydrogen fusion in their core. 
C) They are all spectral type G. 
D) They all have approximately the same mass. 
A) They are in the final stage of their lives. 
B) They generate energy through hydrogen fusion in their core. 
C) They are all spectral type G. 
D) They all have approximately the same mass.

Question 19

Where do we find our star on the H-R diagram?

Accepted Answer

A) In the middle of the main sequence 
B) On the far left of the main sequence 
C) With the red giants 
D) On the lower left 
A) In the middle of the main sequence 
B) On the far left of the main sequence 
C) With the red giants 
D) On the lower left

Question 20

Which of the following statements about spectral types of stars is true?

Accepted Answer

A) The spectral type of a star can be used to determine its surface temperature. 
B) The spectral type of a star can be used to determine its color. 
C) A star with spectral type A is cooler than a star with spectral type B. 
D) A star with spectral type F2 is hotter than a star with spectral type F3. 
E) All of the above are true. 
A) The spectral type of a star can be used to determine its surface temperature. 
B) The spectral type of a star can be used to determine its color. 
C) A star with spectral type A is cooler than a star with spectral type B. 
D) A star with spectral type F2 is hotter than a star with spectral type F3. 
E) All of the above are true.

Exam 15: Surveying the Stars

A star of spectral type O lives approximately how long on the main sequence?

Which has a greater luminosity,a star with absolute magnitude +4 or a star with absolute magnitude -6? By how much is it brighter?

The sketch below shows groups of stars on the H-R diagram labeled (a)through (e).Note that (a)represents the entire main sequence while (c)and (d)represent only small parts of the main sequence. -Which group represents stars of the largest radii?

Process of Science: Why is the classification of stellar spectral types not in alphabetical order?

On a Hertzsprung-Russell diagram,where would we find stars that are cool and dim?

To calculate the masses of stars in a binary system,we must measure their

Which is brighter in our sky,a star with apparent magnitude 2 or a star with apparent magnitude 7? By how much is the star brighter?

Refer to the choices in the table for the following questions. -Which star looks reddest in color?

The spectral sequence in order of decreasing temperature is

Massive,more luminous stars have shorter lives than their smaller,dimmer counterparts.

Two stars,Fred and Barney,are of the same size.Fred has spectral type F,while Barney has spectral type B.Which one is more luminous?

Some stars are cool enough to have molecules in their atmosphere.

Two stars,Tom and Jerry,have the same spectral type.Tom is luminosity class V and Jerry is luminosity class I.Which star is bigger? Which star is more luminous? Which star has a hotter surface temperature? Explain your answers.

What is the approximate chemical composition (by mass)with which all stars are born?

The total amount of power (in watts,for example)that a star radiates into space is called its

Which of the following statements about spectral types of stars is not generally true?

What is the common trait of all main-sequence stars?

Where do we find our star on the H-R diagram?

Which of the following statements about spectral types of stars is true?

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