Question 1

On the H-R diagram, 90 percent of all stars are _______________.

Accepted Answer

The answer of On the H-R diagram, 90 percent of...

Question 2

Our Sun's spectral temperature type is classified as a(n) ____ on the spectral sequence.

Accepted Answer

A)  O star 
B)  F star 
C)  G star 
D)  K star 
E)  M star 
A)  O star 
B)  F star 
C)  G star 
D)  K star 
E)  M star

Question 3

In the accompanying figure, 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

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

Question 4

Recently discovered brown dwarfs have spectra similar to cool O-type stars.

Accepted Answer

A) True 
 B)False

Question 5

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

Question 6

The luminosity (L) of a star is the total energy the star radiates in _______________.

Accepted Answer

One second

Question 7

The classification of stellar spectra started with the amount of hydrogen in the star's spectrum; however, now a better scheme uses the star's _____.

Accepted Answer

A)  mass 
B)  diameter 
C)  radius 
D)  temperature 
E)  luminosity 
A)  mass 
B)  diameter 
C)  radius 
D)  temperature 
E)  luminosity

Question 8

The luminosity of a star is the ____.

Accepted Answer

A)  total energy radiated by the star at 100 parsecs 
B)  total energy radiated by the star 
C)  total energy radiated by the star in one second 
D)  average energy radiated by the star in one month 
E)  average energy radiated by the star in one year 
A)  total energy radiated by the star at 100 parsecs 
B)  total energy radiated by the star 
C)  total energy radiated by the star in one second 
D)  average energy radiated by the star in one month 
E)  average energy radiated by the star in one year

Question 9

The horizontal axis (X-axis) of the Hertzsprung-Russell diagram is labeled with _______________.

Accepted Answer

temperatur

Question 10

If luminosity depends on radius and temperature, what does flux depend on?  _______________

Accepted Answer

The answer of If luminosity depends on radius and temperature,...

Question 11

In the accompanying figure, 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

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

Question 12

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

Accepted Answer

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

Question 13

A star's absolute brightness is calculated at a standard distance of 10 parsecs.

Accepted Answer

A) True 
 B)False

Question 14

Which type of binary system have pairs of stars that are so close together that they look like one single point?

Accepted Answer

A)  radio binary 
B)  eclipsing binary 
C)  visual binary 
D)  spectroscopic binary 
E)  neutron star binary 
A)  radio binary 
B)  eclipsing binary 
C)  visual binary 
D)  spectroscopic binary 
E)  neutron star binary

Question 15

How did astronomers discover the relationship between spectral type and mass for main sequence stars?

Accepted Answer

A)  by measuring stellar radii with very powerful optical telescopes 
B)  by measuring stellar radii with very powerful radio telescopes 
C)  by comparing stars with the same spectral type but different luminosities 
D)  by using computer models of hydrogen fusion and stellar structure 
E)  by measuring the masses and spectral types of main-sequence stars in binary systems 
A)  by measuring stellar radii with very powerful optical telescopes 
B)  by measuring stellar radii with very powerful radio telescopes 
C)  by comparing stars with the same spectral type but different luminosities 
D)  by using computer models of hydrogen fusion and stellar structure 
E)  by measuring the masses and spectral types of main-sequence stars in binary systems

Question 16

On the H-R diagram, 90 percent of all stars are ____.

Accepted Answer

A)  either giant or supergiant stars 
B)  white dwarfs 
C)  main sequence stars 
D)  sred dwarfs 
E)  binary stars 
A)  either giant or supergiant stars 
B)  white dwarfs 
C)  main sequence stars 
D)  sred dwarfs 
E)  binary stars

Question 17

Determine the mass of a theorized black hole from the following information. The mass of the companion main sequence star is 6 solar masses. The observed period and semi-major axis of the binary system are 3.5 years and 5.5 AUs, respectively.

Accepted Answer

The answer of Determine the mass of a theorized black...

Question 18

Stellar spectra started with the amount of hydrogen found in the star's spectrum and started with the letters A through Q.  What are the current letters used to classify stellar spectra?

Accepted Answer

The answer of Stellar spectra started with the amount of...

Question 19

Groombridge 34 i s an M2 main sequence star . Base d o n thi s informatio n, whic h statement is true?

Accepted Answer

A)  Groombridge 34 has a surface temperature that is more than the Sun. 
B)  Groombridge 34 has mass that is greater than the Sun. 
C)  Groombridge 34 is less luminous than the Sun. 
D)  Groombridge 34 is more luminous than the Sun. 
E)  Groombridge 34 is located near the upper left hand corner on the HR diagram. 
A)  Groombridge 34 has a surface temperature that is more than the Sun. 
B)  Groombridge 34 has mass that is greater than the Sun. 
C)  Groombridge 34 is less luminous than the Sun. 
D)  Groombridge 34 is more luminous than the Sun. 
E)  Groombridge 34 is located near the upper left hand corner on the HR diagram.

Question 20

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

Exam 9: The Family of Stars

On the H-R diagram, 90 percent of all stars are _______________.

Our Sun's spectral temperature type is classified as a(n) ____ on the spectral sequence.

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

Recently discovered brown dwarfs have spectra similar to cool O-type stars.

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

The luminosity (L) of a star is the total energy the star radiates in _______________.

The classification of stellar spectra started with the amount of hydrogen in the star's spectrum; however, now a better scheme uses the star's _____.

The luminosity of a star is the ____.

The horizontal axis (X-axis) of the Hertzsprung-Russell diagram is labeled with _______________.

If luminosity depends on radius and temperature, what does flux depend on? _______________

In the accompanying figure, 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?

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

A star's absolute brightness is calculated at a standard distance of 10 parsecs.

Which type of binary system have pairs of stars that are so close together that they look like one single point?

How did astronomers discover the relationship between spectral type and mass for main sequence stars?

On the H-R diagram, 90 percent of all stars are ____.

Determine the mass of a theorized black hole from the following information. The mass of the companion main sequence star is 6 solar masses. The observed period and semi-major axis of the binary system are 3.5 years and 5.5 AUs, respectively.

Stellar spectra started with the amount of hydrogen found in the star's spectrum and started with the letters A through Q. What are the current letters used to classify stellar spectra?

Groombridge 34 i s an M2 main sequence star . Base d o n thi s informatio n, whic h statement is true?

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

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Origins of Modern Astronomy

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