Question 1

For which type of binary system are astronomers able to resolve each of the two stars individually?

Accepted Answer

A)  eclipsing binary 
B)  spectroscopic binary 
C)  visual binary 
D)  binaries where the two stars have the same mass 
E)  binaries where the two stars have the same luminosity 
A)  eclipsing binary 
B)  spectroscopic binary 
C)  visual binary 
D)  binaries where the two stars have the same mass 
E)  binaries where the two stars have the same luminosity C

Question 2

A star classified as a K0III star is:

Accepted Answer

A)  a giant that is cooler than the Sun 
B)  a supergiant that is hotter than the Sun 
C)  a main-sequence star that is hotter than the Sun 
D)  a subgiant that is cooler than the Sun 
E)  a dwarf that is hotter than the Sun 
A)  a giant that is cooler than the Sun 
B)  a supergiant that is hotter than the Sun 
C)  a main-sequence star that is hotter than the Sun 
D)  a subgiant that is cooler than the Sun 
E)  a dwarf that is hotter than the Sun A

Question 3

Spectra of the least massive main-sequence stars show the largest amount of absorption from molecules like TiO and CN.

Accepted Answer

A) True 
 B)False  True

Question 4

The bright star Arcturus has a luminosity of 210 L $\odot$  and a temperature of 4300 K. What is its radius? Note that the Sun has a temperature of 5800 K.

Accepted Answer

Using the Stefan-Boltzmann law

Question 5

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 in a binary

Question 6

The fraction of the Sun's mass that is made of heavy elements is:

Accepted Answer

A)  0.5 percent 
B)  2 percent 
C)  10 percent 
D)  20 percent 
E)  50 percent 
A)  0.5 percent 
B)  2 percent 
C)  10 percent 
D)  20 percent 
E)  50 percent

Question 7

The star named Capella has an apparent magnitude of 0, while the star named Polaris has an apparent magnitude of 2, which means that Capella is _________ than Polaris.

Accepted Answer

A)  18 times fainter 
B)  6 times fainter 
C)  2 times fainter 
D)  2 times brighter 
E)  6 times brighter 
A)  18 times fainter 
B)  6 times fainter 
C)  2 times fainter 
D)  2 times brighter 
E)  6 times brighter

Question 8

With today's advanced technology, we can measure the parallax for any star inside the Milky Way.

Accepted Answer

A) True 
 B)False

Question 9

Which sequence correctly lists the spectral classes of stars in order from hottest to coolest?

Accepted Answer

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

Question 10

Star C is a red star. Star D is a blue star. Which has a larger radius?

Accepted Answer

A)  Star C has a larger radius. 
B)  Star D has a larger radius. 
C)  Stars C and D have the same radius. 
D)  We also need to know the luminosities of the stars to determine their radii. 
E)  We cannot determine the radii because color is not related to the radius. 
A)  Star C has a larger radius. 
B)  Star D has a larger radius. 
C)  Stars C and D have the same radius. 
D)  We also need to know the luminosities of the stars to determine their radii. 
E)  We cannot determine the radii because color is not related to the radius.

Question 11

The stars that have the largest radii are classified as:

Accepted Answer

A)  giants 
B)  ultragiants 
C)  supergiants 
D)  megagiants 
E)  supernovae 
A)  giants 
B)  ultragiants 
C)  supergiants 
D)  megagiants 
E)  supernovae

Question 12

You observe two stars in a visual binary system using a blue filter that is centered at a wavelength of 550 nm and a red filter that is centered at a wavelength of 650 nm. Star A has a temperature of 10,000 K, while star B has a temperature of 4000 K, and you know that both stars are the same size. Which star will be the brightest in each filter?

Accepted Answer

A)  Star A is the brightest in the blue filter, and star B is the brightest in the red filter. 
B)  Star B is the brightest in the blue filter, and star A is the brightest in the red filter. 
C)  Star A is the brightest in both filters. 
D)  Star B is the brightest in both filters. 
E)  Both stars have the same brightness in each filter. 
A)  Star A is the brightest in the blue filter, and star B is the brightest in the red filter. 
B)  Star B is the brightest in the blue filter, and star A is the brightest in the red filter. 
C)  Star A is the brightest in both filters. 
D)  Star B is the brightest in both filters. 
E)  Both stars have the same brightness in each filter.

Question 13

If the Hubble space telescope can see stars as faint as magnitude 27, how much fainter are these stars than the faintest ones you can see in a very dark night sky, which have magnitude 6?

Accepted Answer

The Hubble space telescope can

Question 14

What type of spectrum do most stars produce?

Accepted Answer

A)  an absorption spectrum on top of a blackbody spectrum 
B)  an emission spectrum on top of a blackbody spectrum 
C)  an absorption spectrum on top of an emission spectrum 
D)  a pure emission spectrum 
E)  a pure blackbody spectrum 
A)  an absorption spectrum on top of a blackbody spectrum 
B)  an emission spectrum on top of a blackbody spectrum 
C)  an absorption spectrum on top of an emission spectrum 
D)  a pure emission spectrum 
E)  a pure blackbody spectrum

Question 15

If we know the temperature and luminosity of a star, we can also calculate its:

Accepted Answer

A)  radius 
B)  mass 
C)  chemical composition 
D)  brightness 
E)  all of the above 
A)  radius 
B)  mass 
C)  chemical composition 
D)  brightness 
E)  all of the above

Question 16

What type of star is most common in the solar neighborhood?

Accepted Answer

A)  subgiants 
B)  supergiant 
C)  white dwarf 
D)  giant 
E)  main-sequence 
A)  subgiants 
B)  supergiant 
C)  white dwarf 
D)  giant 
E)  main-sequence

Question 17

How many arcseconds are there in 1 degree?

Accepted Answer

A)  60 
B)  360 
C)  3,600 
D)  6,000 
E)  36,000 
A)  60 
B)  360 
C)  3,600 
D)  6,000 
E)  36,000

Question 18

Star A emits its peak energy at a wavelength of 500 nm, and star B emits its peak energy at a wavelength of 750 nm. If both stars have the same radii, which star is hotter and by how much?

Accepted Answer

By Wien's law, the temperature of a star

Question 19

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 
E)  1 arcsec 
A)  0.01 arcsec 
B)  0.05 arcsec 
C)  0.1 arcsec 
D)  0.5 arcsec 
E)  1 arcsec

Question 20

The one property of a main-sequence star that determines all its other properties is its:

Accepted Answer

A)  luminosity 
B)  mass 
C)  temperature 
D)  spectral type 
E)  brightness 
A)  luminosity 
B)  mass 
C)  temperature 
D)  spectral type 
E)  brightness

Exam 13: Taking the Measure of Stars

For which type of binary system are astronomers able to resolve each of the two stars individually?

A star classified as a K0III star is:

Spectra of the least massive main-sequence stars show the largest amount of absorption from molecules like TiO and CN.

The bright star Arcturus has a luminosity of 210 L ⊙\odot⊙ and a temperature of 4300 K. What is its radius? Note that the Sun has a temperature of 5800 K.

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)?

The fraction of the Sun's mass that is made of heavy elements is:

The star named Capella has an apparent magnitude of 0, while the star named Polaris has an apparent magnitude of 2, which means that Capella is _________ than Polaris.

With today's advanced technology, we can measure the parallax for any star inside the Milky Way.

Which sequence correctly lists the spectral classes of stars in order from hottest to coolest?

Star C is a red star. Star D is a blue star. Which has a larger radius?

The stars that have the largest radii are classified as:

If the Hubble space telescope can see stars as faint as magnitude 27, how much fainter are these stars than the faintest ones you can see in a very dark night sky, which have magnitude 6?

What type of spectrum do most stars produce?

If we know the temperature and luminosity of a star, we can also calculate its:

What type of star is most common in the solar neighborhood?

How many arcseconds are there in 1 degree?

Star A emits its peak energy at a wavelength of 500 nm, and star B emits its peak energy at a wavelength of 750 nm. If both stars have the same radii, which star is hotter and by how much?

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

The one property of a main-sequence star that determines all its other properties is its:

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters

The bright star Arcturus has a luminosity of 210 L _$\odot$ and a temperature of 4300 K. What is its radius? Note that the Sun has a temperature of 5800 K.

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)?