Question 1

How many stars of sixth-magnitude would it take for a small cluster to appear as bright as a single first-magnitude star?

Accepted Answer

A)  105 
B)  5 
C)  6 
D)  100 
A)  105 
B)  5 
C)  6 
D)  100 D

Question 2

A star with a surface temperature of 5000 K and a luminosity greater than 104 times that of the Sun is a member of which luminosity class?

Accepted Answer

A)  IV, subgiant 
B)  V, main sequence 
C)  III, giant 
D)  I, supergiant 
A)  IV, subgiant 
B)  V, main sequence 
C)  III, giant 
D)  I, supergiant D

Question 3

What is parallax?

Accepted Answer

A)  distance to an object, measured in parsecs 
B)  angle taken up by the size (e.g., diameter) of an object, as seen by an observer 
C)  shift in angular position of an object as it moves in space 
D)  apparent shift in position of an object as the observer moves 
A)  distance to an object, measured in parsecs 
B)  angle taken up by the size (e.g., diameter) of an object, as seen by an observer 
C)  shift in angular position of an object as it moves in space 
D)  apparent shift in position of an object as the observer moves D

Question 4

How far out into space can distances be determined using telescopes on Earth if stellar parallax values no smaller than 0.01 arcsec can be measured?

Accepted Answer

A)  10 pc 
B)  100 pc 
C)  500 pc 
D)  2000 pc 
A)  10 pc 
B)  100 pc 
C)  500 pc 
D)  2000 pc

Question 5

A particular star has an absolute magnitude of 0 and a spectral class similar to that of the Sun. Using Figure 12-10 in the text, how would this star be classified?

Accepted Answer

A)  G2 V 
B)  G-type white dwarf 
C)  G2 I 
D)  G2 III 
A)  G2 V 
B)  G-type white dwarf 
C)  G2 I 
D)  G2 III

Question 6

The star Alderamin has an apparent magnitude of 2.4 and an absolute magnitude of 1.4. From this information (assuming that the starlight has not been dimmed by interstellar clouds), one can say for sure that Alderamin is _____.

Accepted Answer

A)  less than 10 pc away 
B)  brightest in blue light 
C)  brightest in red light 
D)  more than 10 pc away 
A)  less than 10 pc away 
B)  brightest in blue light 
C)  brightest in red light 
D)  more than 10 pc away

Question 7

The semimajor axis of Pluto's orbit is almost 40 au. From its orbit around Earth, the Hipparcos satellite measured stellar parallaxes to an accuracy of about 0.01 arcsecond. Suppose astronomers use this technique to measure parallax from Pluto's orbit (over the course of half a Pluto "year"). What is the maximum distance they could measure?

Accepted Answer

A)  4 pc 
B)  100 pc 
C)  4000 pc 
D)  8000 pc 
A)  4 pc 
B)  100 pc 
C)  4000 pc 
D)  8000 pc

Question 8

Stellar parallax is the

Accepted Answer

A)  inferred change in the distance to a star as its light is dimmed by passing through an interstellar cloud. 
B)  apparent shift seen in the position of a nearby star against more distant stars as Earth orbits the Sun. 
C)  difference between the apparent and absolute magnitudes of a star. 
D)  circular or elliptical motion of a star in a binary system as the two stars orbit each other. 
A)  inferred change in the distance to a star as its light is dimmed by passing through an interstellar cloud. 
B)  apparent shift seen in the position of a nearby star against more distant stars as Earth orbits the Sun. 
C)  difference between the apparent and absolute magnitudes of a star. 
D)  circular or elliptical motion of a star in a binary system as the two stars orbit each other.

Question 9

See Figure 12-10 in the text. The star $\zeta$ Canis Majoris has an absolute magnitude of -2.4 and a spectral luminosity class of B2 V. The star $\gamma$ Crucis has a spectral class of M4 and the same absolute magnitude as Canis Majoris. The spectral luminosity class of Crucis is probably

Accepted Answer

A)  M-type white dwarf. 
B)  M4 II. 
C)  M4 Ia. 
D)  M4 V. 
A)  M-type white dwarf. 
B)  M4 II. 
C)  M4 Ia. 
D)  M4 V.

Question 10

The MOST straightforward way to determine the distance to a nearby star involves the measurement of the

Accepted Answer

A)  star's spectrum. 
B)  ratio of the star's apparent and absolute magnitudes. 
C)  Zeeman effect of spectral lines in the star's spectrum. 
D)  star's parallax. 
A)  star's spectrum. 
B)  ratio of the star's apparent and absolute magnitudes. 
C)  Zeeman effect of spectral lines in the star's spectrum. 
D)  star's parallax.

Question 11

Which of these major perturbations can occur to a close binary system and radically alter the evolution and behavior of the two individual stars?

Accepted Answer

A)  gravitational disturbance of one star's motion by its companion to force it to move in an orbit 
B)  transfer of matter from one star to its companion 
C)  heating of the localized areas of the atmosphere of one star by its companion 
D)  eclipsing of the light from one star by the other when viewed from Earth 
A)  gravitational disturbance of one star's motion by its companion to force it to move in an orbit 
B)  transfer of matter from one star to its companion 
C)  heating of the localized areas of the atmosphere of one star by its companion 
D)  eclipsing of the light from one star by the other when viewed from Earth

Question 12

Two stars have the same luminosity (or absolute magnitude). One star is spectral class B and the other is spectral class K. From this information, one knows that the

Accepted Answer

A)  K-type star is larger than the B-type star. 
B)  B-type star is larger than the K-type star. 
C)  B-type star is hotter but can be larger, smaller, or the same size as the K-type star. 
D)  K-type star is hotter but can be larger, smaller, or the same size as the B-type star. 
A)  K-type star is larger than the B-type star. 
B)  B-type star is larger than the K-type star. 
C)  B-type star is hotter but can be larger, smaller, or the same size as the K-type star. 
D)  K-type star is hotter but can be larger, smaller, or the same size as the B-type star.

Question 13

The equation for the luminosity of a star in terms of its surface temperature is L = (surface area) $\sigma$T4 where $\sigma$ is the Stefan-Boltzmann constant. This suggests that when a plot is made of luminosities versus temperature

Accepted Answer

A)  stars of the same temperature but different radii should occupy different points on the plot. 
B)  all stars should plot along the line. 
C)  larger stars must have higher temperatures. 
D)  smaller stars must have higher temperatures. 
A)  stars of the same temperature but different radii should occupy different points on the plot. 
B)  all stars should plot along the line. 
C)  larger stars must have higher temperatures. 
D)  smaller stars must have higher temperatures.

Question 14

Absorption line strengths are used in the spectral classification of stars and the determination of surface temperatures. Which of these atomic or molecular constituents exhibits strong absorption lines in spectra from stars with very high surface temperature?

Accepted Answer

A)  H 
B)  Ca II 
C)  He II 
D)  TiO 
A)  H 
B)  Ca II 
C)  He II 
D)  TiO

Question 15

A star is at such a distance that its apparent magnitude (m) is 10 magnitudes fainter than its absolute magnitude (M). How far away is it?

Accepted Answer

A)  10 pc 
B)  100 pc 
C)  1000 pc 
D)  10,000 pc 
A)  10 pc 
B)  100 pc 
C)  1000 pc 
D)  10,000 pc

Question 16

The motion that is used to change the position of the observer in the most common parallax measurements of distances to relatively nearby stars is the

Accepted Answer

A)  motion of the Sun around the galactic center. 
B)  change in latitude of the observation point on Earth. 
C)  motion of Earth in its orbit around the Sun. 
D)  rotation of Earth on its axis. 
A)  motion of the Sun around the galactic center. 
B)  change in latitude of the observation point on Earth. 
C)  motion of Earth in its orbit around the Sun. 
D)  rotation of Earth on its axis.

Question 17

The star Arietis has an apparent magnitude of +2.7 and a distance of 52 ly. What is its absolute magnitude?

Accepted Answer

A)  +1.7 
B)  -0.9 
C)  +6.2 
D)  +3.7 
A)  +1.7 
B)  -0.9 
C)  +6.2 
D)  +3.7

Question 18

Two of the brightest stars in Orion are Betelgeuse (apparent magnitude = 0.45) and Rigel (apparent magnitude = 0.15). From this information, one can determine

Accepted Answer

A)  that Betelgeuse is brighter than Rigel. 
B)  that Betelgeuse is bigger than Rigel. 
C)  that Betelgeuse is farther away than Rigel. 
D)  None of these are correct. 
A)  that Betelgeuse is brighter than Rigel. 
B)  that Betelgeuse is bigger than Rigel. 
C)  that Betelgeuse is farther away than Rigel. 
D)  None of these are correct.

Question 19

How bright (in absolute magnitude) are the intrinsically brightest stars in the universe?

Accepted Answer

A)  +17 
B)  +1 
C)  0 
D)  -10 
A)  +17 
B)  +1 
C)  0 
D)  -10

Question 20

Which of these observations would NOT be an indication of a binary star system?

Accepted Answer

A)  The "star" appears to move in a straight line against a background field of stars. 
B)  A "star" appears to become periodically dimmer and then brighter for a few hours at a time. 
C)  A "star" image periodically separates into two distinct images and then blends again. 
D)  The "star" appears to wiggle in its path across Earth's sky against the background stars. 
A)  The "star" appears to move in a straight line against a background field of stars. 
B)  A "star" appears to become periodically dimmer and then brighter for a few hours at a time. 
C)  A "star" image periodically separates into two distinct images and then blends again. 
D)  The "star" appears to wiggle in its path across Earth's sky against the background stars.

How many stars of sixth-magnitude would it take for a small cluster to appear as bright as a single first-magnitude star?

A star with a surface temperature of 5000 K and a luminosity greater than 10⁴ times that of the Sun is a member of which luminosity class?

What is parallax?

How far out into space can distances be determined using telescopes on Earth if stellar parallax values no smaller than 0.01 arcsec can be measured?

A particular star has an absolute magnitude of 0 and a spectral class similar to that of the Sun. Using Figure 12-10 in the text, how would this star be classified?

The star Alderamin has an apparent magnitude of 2.4 and an absolute magnitude of 1.4. From this information (assuming that the starlight has not been dimmed by interstellar clouds), one can say for sure that Alderamin is _____.

Stellar parallax is the

The MOST straightforward way to determine the distance to a nearby star involves the measurement of the

Which of these major perturbations can occur to a close binary system and radically alter the evolution and behavior of the two individual stars?

Two stars have the same luminosity (or absolute magnitude). One star is spectral class B and the other is spectral class K. From this information, one knows that the

The equation for the luminosity of a star in terms of its surface temperature is L = (surface area) $\sigma$ T⁴ where $\sigma$ is the Stefan-Boltzmann constant. This suggests that when a plot is made of luminosities versus temperature

Absorption line strengths are used in the spectral classification of stars and the determination of surface temperatures. Which of these atomic or molecular constituents exhibits strong absorption lines in spectra from stars with very high surface temperature?

A star is at such a distance that its apparent magnitude (m) is 10 magnitudes fainter than its absolute magnitude (M). How far away is it?

The motion that is used to change the position of the observer in the most common parallax measurements of distances to relatively nearby stars is the

The star Arietis has an apparent magnitude of +2.7 and a distance of 52 ly. What is its absolute magnitude?

Two of the brightest stars in Orion are Betelgeuse (apparent magnitude = 0.45) and Rigel (apparent magnitude = 0.15). From this information, one can determine

How bright (in absolute magnitude) are the intrinsically brightest stars in the universe?

Which of these observations would NOT be an indication of a binary star system?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 12: Characterizing Stars

How many stars of sixth-magnitude would it take for a small cluster to appear as bright as a single first-magnitude star?

A star with a surface temperature of 5000 K and a luminosity greater than 104 times that of the Sun is a member of which luminosity class?

What is parallax?

How far out into space can distances be determined using telescopes on Earth if stellar parallax values no smaller than 0.01 arcsec can be measured?

A particular star has an absolute magnitude of 0 and a spectral class similar to that of the Sun. Using Figure 12-10 in the text, how would this star be classified?

The star Alderamin has an apparent magnitude of 2.4 and an absolute magnitude of 1.4. From this information (assuming that the starlight has not been dimmed by interstellar clouds), one can say for sure that Alderamin is _____.

Stellar parallax is the

See Figure 12-10 in the text. The star ζ\zetaζ Canis Majoris has an absolute magnitude of -2.4 and a spectral luminosity class of B2 V. The star γ\gammaγ Crucis has a spectral class of M4 and the same absolute magnitude as Canis Majoris. The spectral luminosity class of Crucis is probably

The MOST straightforward way to determine the distance to a nearby star involves the measurement of the

Which of these major perturbations can occur to a close binary system and radically alter the evolution and behavior of the two individual stars?

Two stars have the same luminosity (or absolute magnitude). One star is spectral class B and the other is spectral class K. From this information, one knows that the

The equation for the luminosity of a star in terms of its surface temperature is L = (surface area) σ\sigmaσ T4 where σ\sigmaσ is the Stefan-Boltzmann constant. This suggests that when a plot is made of luminosities versus temperature

Absorption line strengths are used in the spectral classification of stars and the determination of surface temperatures. Which of these atomic or molecular constituents exhibits strong absorption lines in spectra from stars with very high surface temperature?

A star is at such a distance that its apparent magnitude (m) is 10 magnitudes fainter than its absolute magnitude (M). How far away is it?

The motion that is used to change the position of the observer in the most common parallax measurements of distances to relatively nearby stars is the

The star Arietis has an apparent magnitude of +2.7 and a distance of 52 ly. What is its absolute magnitude?

Two of the brightest stars in Orion are Betelgeuse (apparent magnitude = 0.45) and Rigel (apparent magnitude = 0.15). From this information, one can determine

How bright (in absolute magnitude) are the intrinsically brightest stars in the universe?

Which of these observations would NOT be an indication of a binary star system?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

A star with a surface temperature of 5000 K and a luminosity greater than 10⁴ times that of the Sun is a member of which luminosity class?

The equation for the luminosity of a star in terms of its surface temperature is L = (surface area) $\sigma$ T⁴ where $\sigma$ is the Stefan-Boltzmann constant. This suggests that when a plot is made of luminosities versus temperature