Question 1

How is the unit of length known as a parsec defined?

Accepted Answer

The parsec is defined such tha

Question 2

To measure the parallax of the most distant stars measurable,we would make two measurements of the star's position separated by:

Accepted Answer

A)  6 hours 
B)  12 hours 
C)  6 months 
D)  12 months 
A)  6 hours 
B)  12 hours 
C)  6 months 
D)  12 months

Question 3

When an electron moves from a higher energy level in an atom to a lower energy level:

Accepted Answer

A)  the atom is ionized 
B)  a continuous spectrum is emitted 
C)  a photon is emitted 
D)  a photon is absorbed 
A)  the atom is ionized 
B)  a continuous spectrum is emitted 
C)  a photon is emitted 
D)  a photon is absorbed

Question 4

If a star's measured parallax is 0.2 arcsec,what is its distance?

Accepted Answer

A)  5 pc 
B)  20 pc 
C)  40 pc 
D)  50 pc 
A)  5 pc 
B)  20 pc 
C)  40 pc 
D)  50 pc

Question 5

The spectral class of a star is related to its:

Accepted Answer

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

Question 6

B stars are cooler than M stars.

Accepted Answer

A) True 
 B)False

Question 7

Main-sequence stars range in mass from approximately:

Accepted Answer

A)  0.5 to 10 M$\bigodot$ 
B)  0.08 to 140 M$\bigodot$ 
C)  1 to 100 M$\bigodot$ 
D)  0.1 to 75 M$\bigodot$ 
A)  0.5 to 10 M$\bigodot$ 
B)  0.08 to 140 M$\bigodot$ 
C)  1 to 100 M$\bigodot$ 
D)  0.1 to 75 M$\bigodot$

Question 8

Stars A and B appear equally bright,but star A is twice as far away from us as star B.Which of the following is true?

Accepted Answer

A)  Star A is twice as luminous as star B. 
B)  Star A is four times as luminous as star B. 
C)  Star B is twice as luminous as star A. 
D)  Star B is four times as luminous as star B. 
A)  Star A is twice as luminous as star B. 
B)  Star A is four times as luminous as star B. 
C)  Star B is twice as luminous as star A. 
D)  Star B is four times as luminous as star B.

Question 9

Binary star systems are extremely useful in studying stars because they allow us to determine stars' masses.

Accepted Answer

A) True 
 B)False

Question 10

Examine the figure below.Along the main sequence,how do the luminosity,temperature,radius,and mass of stars change as you go from the upper-left to the lower-right corners of the H-R diagram?

Accepted Answer

Stars near the upper-left end

Question 11

You observe a binary star system and find that star 1 has a velocity of 10 m/s while star 2 has a velocity of 35 m/s.What is the ratio of masses of the two stars (M1/M2)?

Accepted Answer

The ratio of masses of stars i

Question 12

Describe the luminosity classes found on the H-R diagram below.

Accepted Answer

The luminosity classes on the

Question 13

What is the main property of a main-sequence star that determines nearly all its other properties?

Accepted Answer

The star's mass has

Question 14

Mass determines the position of a star on the main sequence.

Accepted Answer

A) True 
 B)False

Question 15

If given the image in the figure below alone,what further information might be required to determine that the stars are a visual binary system?

Accepted Answer

To determine that the stars ar

Question 16

Roughly what percentage of stars are main-sequence stars?

Accepted Answer

A)  10 percent 
B)  40 percent 
C)  60 percent 
D)  90 percent 
A)  10 percent 
B)  40 percent 
C)  60 percent 
D)  90 percent

Question 17

Heisenberg's uncertainty principle tells us that an electron in an atom behaves more like a cloud than a pointlike particle.

Accepted Answer

A) True 
 B)False

Question 18

Star A is a red star.Star B is a blue star.Which is hotter?

Accepted Answer

A)  Star A 
B)  Star B 
C)  We also need to know the luminosities of the stars to determine their temperatures. 
D)  Color is not related to temperature at all. 
A)  Star A 
B)  Star B 
C)  We also need to know the luminosities of the stars to determine their temperatures. 
D)  Color is not related to temperature at all.

Question 19

Stars of spectral class A have the most hydrogen whereas stars of spectral class O have the least hydrogen.

Accepted Answer

A) True 
 B)False

Question 20

If a star's distance is 10 pc,what is its parallax?

Accepted Answer

A)  0.01 arcsec 
B)  0.05 arcsec 
C)  0.1 arcsec 
D)  0.5 arcsec 
A)  0.01 arcsec 
B)  0.05 arcsec 
C)  0.1 arcsec 
D)  0.5 arcsec

How is the unit of length known as a parsec defined?

To measure the parallax of the most distant stars measurable,we would make two measurements of the star's position separated by:

When an electron moves from a higher energy level in an atom to a lower energy level:

If a star's measured parallax is 0.2 arcsec,what is its distance?

The spectral class of a star is related to its:

B stars are cooler than M stars.

Main-sequence stars range in mass from approximately:

Stars A and B appear equally bright,but star A is twice as far away from us as star B.Which of the following is true?

Binary star systems are extremely useful in studying stars because they allow us to determine stars' masses.

Examine the figure below.Along the main sequence,how do the luminosity,temperature,radius,and mass of stars change as you go from the upper-left to the lower-right corners of the H-R diagram?

You observe a binary star system and find that star 1 has a velocity of 10 m/s while star 2 has a velocity of 35 m/s.What is the ratio of masses of the two stars (M₁/M₂)?

Describe the luminosity classes found on the H-R diagram below.

What is the main property of a main-sequence star that determines nearly all its other properties?

Mass determines the position of a star on the main sequence.

If given the image in the figure below alone,what further information might be required to determine that the stars are a visual binary system?

Roughly what percentage of stars are main-sequence stars?

Heisenberg's uncertainty principle tells us that an electron in an atom behaves more like a cloud than a pointlike particle.

Star A is a red star.Star B is a blue star.Which is hotter?

Stars of spectral class A have the most hydrogen whereas stars of spectral class O have the least hydrogen.

If a star's distance is 10 pc,what is its parallax?

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Our Star: The Sun

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

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Exam 10: Measuring the Stars

How is the unit of length known as a parsec defined?

To measure the parallax of the most distant stars measurable,we would make two measurements of the star's position separated by:

When an electron moves from a higher energy level in an atom to a lower energy level:

If a star's measured parallax is 0.2 arcsec,what is its distance?

The spectral class of a star is related to its:

B stars are cooler than M stars.

Main-sequence stars range in mass from approximately:

Stars A and B appear equally bright,but star A is twice as far away from us as star B.Which of the following is true?

Binary star systems are extremely useful in studying stars because they allow us to determine stars' masses.

Examine the figure below.Along the main sequence,how do the luminosity,temperature,radius,and mass of stars change as you go from the upper-left to the lower-right corners of the H-R diagram?

You observe a binary star system and find that star 1 has a velocity of 10 m/s while star 2 has a velocity of 35 m/s.What is the ratio of masses of the two stars (M1/M2)?

Describe the luminosity classes found on the H-R diagram below.

What is the main property of a main-sequence star that determines nearly all its other properties?

Mass determines the position of a star on the main sequence.

If given the image in the figure below alone,what further information might be required to determine that the stars are a visual binary system?

Roughly what percentage of stars are main-sequence stars?

Heisenberg's uncertainty principle tells us that an electron in an atom behaves more like a cloud than a pointlike particle.

Star A is a red star.Star B is a blue star.Which is hotter?

Stars of spectral class A have the most hydrogen whereas stars of spectral class O have the least hydrogen.

If a star's distance is 10 pc,what is its parallax?

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Our Star: The Sun

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

Filters

You observe a binary star system and find that star 1 has a velocity of 10 m/s while star 2 has a velocity of 35 m/s.What is the ratio of masses of the two stars (M₁/M₂)?