Question 1

From its position on the Hertzsprung-Russell diagram in Figure 12-7 in the text, what can an astronomer conclude about the star Mira compared with the Sun?

Accepted Answer

A)  Mira is cooler and redder but intrinsically brighter than the Sun. 
B)  Mira is cooler, redder, and intrinsically fainter than the Sun. 
C)  Mira is hotter than the Sun and intrinsically brighter. 
D)  Mira is hotter and bluer but intrinsically fainter than the Sun. 
A)  Mira is cooler and redder but intrinsically brighter than the Sun. 
B)  Mira is cooler, redder, and intrinsically fainter than the Sun. 
C)  Mira is hotter than the Sun and intrinsically brighter. 
D)  Mira is hotter and bluer but intrinsically fainter than the Sun.

Question 2

The technical designation for the bright star Regulus is $\alpha$ Leonis. This means that Regulus is

Accepted Answer

A)  the second brightest star in the constellation Leon the Astronomer. 
B)  the third brightest star in the constellation Leo the Leopard. 
C)  the brightest star in the constellation Leo the Lion. 
D)  a star of spectral type alpha in the constellation Leo. 
A)  the second brightest star in the constellation Leon the Astronomer. 
B)  the third brightest star in the constellation Leo the Leopard. 
C)  the brightest star in the constellation Leo the Lion. 
D)  a star of spectral type alpha in the constellation Leo.

Question 3

An eclipsing binary system consists of

Accepted Answer

A)  a star that is periodically eclipsed by the Moon. 
B)  two stars that periodically eclipse each other, as seen from Earth. 
C)  two stars in which spectral lines move back and forth periodically due to Doppler shift, indicating mutually orbiting stars. 
D)  two mutually orbiting and gravitationally bound stars that are close enough to be resolved when viewed from Earth. 
A)  a star that is periodically eclipsed by the Moon. 
B)  two stars that periodically eclipse each other, as seen from Earth. 
C)  two stars in which spectral lines move back and forth periodically due to Doppler shift, indicating mutually orbiting stars. 
D)  two mutually orbiting and gravitationally bound stars that are close enough to be resolved when viewed from Earth.

Question 4

A star with a surface temperature of 4000 K and a luminosity of about 10-2 times that of the Sun is a member of which luminosity class? See Figure 12-10 from the text.

Accepted Answer

A)  III, giant 
B)  I, supergiant 
C)  II, bright giant 
D)  V, main sequence 
A)  III, giant 
B)  I, supergiant 
C)  II, bright giant 
D)  V, main sequence

Question 5

The surface temperature of a nearby star can be determined MOST precisely by measuring what parameters?

Accepted Answer

A)  position of the star on the H-R diagram 
B)  Doppler shift of the star's spectral lines 
C)  relative strengths of emission lines from different atoms and ions in the star's spectrum 
D)  relative strengths of absorption lines from different atoms (e.g., H, Ca) and molecules (e.g., TiO) in the star's spectrum 
A)  position of the star on the H-R diagram 
B)  Doppler shift of the star's spectral lines 
C)  relative strengths of emission lines from different atoms and ions in the star's spectrum 
D)  relative strengths of absorption lines from different atoms (e.g., H, Ca) and molecules (e.g., TiO) in the star's spectrum

Question 6

If an observer looks out at a clear night sky with the unaided eye, the faintest stars the observer can see have magnitudes around

Accepted Answer

A)  -6 
B)  0 
C)  +6 
D)  +12 
A)  -6 
B)  0 
C)  +6 
D)  +12

Question 7

If the intrinsically faintest stars in Earth's sky have absolute magnitudes of +17, how does their total energy output compare with that of the Sun, whose absolute magnitude is +4.8?

Accepted Answer

A)  about 12.2 times lower 
B)  about 1012 or 1,000,000,000,000, times lower 
C)  about 7600 times lower 
D)  about 76,000 times lower 
A)  about 12.2 times lower 
B)  about 1012 or 1,000,000,000,000, times lower 
C)  about 7600 times lower 
D)  about 76,000 times lower

Question 8

A star of apparent magnitude +3.5 appears _____ than a star of apparent magnitude +3.3.

Accepted Answer

A)  farther away 
B)  fainter 
C)  either brighter or fainter, depending on the distance to the stars, 
D)  brighter 
A)  farther away 
B)  fainter 
C)  either brighter or fainter, depending on the distance to the stars, 
D)  brighter

Question 9

Which one of these is NOT needed to compute a distance to a star by the spectroscopic parallax method?

Accepted Answer

A)  the mathematical relationship among distance, absolute magnitude, and apparent magnitude 
B)  the star's stellar parallax 
C)  the star's apparent magnitude 
D)  the star's luminosity 
A)  the mathematical relationship among distance, absolute magnitude, and apparent magnitude 
B)  the star's stellar parallax 
C)  the star's apparent magnitude 
D)  the star's luminosity

Question 10

A star has a surface temperature of 6000 K. Its spectrum registers a certain intensity in the green middle of the visible spectrum. Which of these must also be true of the star?

Accepted Answer

A)  Violet is brighter than the green but the red is less intense. 
B)  Violet is less intense than the green but the red is more intense. 
C)  Violet and the red are both less intense than the green. 
D)  Violet and the red are both more intense than the green. 
A)  Violet is brighter than the green but the red is less intense. 
B)  Violet is less intense than the green but the red is more intense. 
C)  Violet and the red are both less intense than the green. 
D)  Violet and the red are both more intense than the green.

Question 11

A star is 80 pc from the Sun. Its apparent motion against the background sky, that is, its stellar parallax, as a result of Earth's motion through 1 au is

Accepted Answer

A)  0.0125 arcsecond. 
B)  0.0125 arcminute. 
C)  0.0125 radian or 0.72 $\degree$. 
D)  80 arcseconds. 
A)  0.0125 arcsecond. 
B)  0.0125 arcminute. 
C)  0.0125 radian or 0.72 $\degree$. 
D)  80 arcseconds.

Question 12

A star of apparent magnitude +2.1 appears _____ than a star of apparent magnitude -1.2.

Accepted Answer

A)  farther away 
B)  fainter 
C)  brighter 
D)  either brighter or fainter, depending on the distance to the stars, 
A)  farther away 
B)  fainter 
C)  brighter 
D)  either brighter or fainter, depending on the distance to the stars,

Question 13

As an observer moves closer to a star, which two of its properties change?

Accepted Answer

A)  luminosity and absolute magnitude 
B)  luminosity and apparent brightness 
C)  absolute magnitude and brightness 
D)  apparent magnitude and brightness 
A)  luminosity and absolute magnitude 
B)  luminosity and apparent brightness 
C)  absolute magnitude and brightness 
D)  apparent magnitude and brightness

Question 14

Spectral types of stars (e.g., O, B, A, F, G, K, and M) uniquely define their

Accepted Answer

A)  sizes or radii. 
B)  absolute magnitudes. 
C)  luminosities. 
D)  surface temperatures. 
A)  sizes or radii. 
B)  absolute magnitudes. 
C)  luminosities. 
D)  surface temperatures.

Question 15

How far away is the nearest star beyond the Sun, in parsecs?

Accepted Answer

A)  between 1 and 2 pc 
B)  about 12 pc 
C)  about 4 pc 
D)  between 1/2 and 1 pc 
A)  between 1 and 2 pc 
B)  about 12 pc 
C)  about 4 pc 
D)  between 1/2 and 1 pc

Question 16

If a certain star shows a strong absorption spectrum in hydrogen Balmer lines, the surface temperature of the star is hot enough that

Accepted Answer

A)  virtually all of the hydrogen atoms are ionized. 
B)  many hydrogen atoms have electrons in the n = 2 energy level. 
C)  many hydrogen atoms have electrons in the n = 3 energy level. 
D)  many helium atoms have been converted to hydrogen atoms. 
A)  virtually all of the hydrogen atoms are ionized. 
B)  many hydrogen atoms have electrons in the n = 2 energy level. 
C)  many hydrogen atoms have electrons in the n = 3 energy level. 
D)  many helium atoms have been converted to hydrogen atoms.

Question 17

Which of these properties of a nearby star is determined by a measurement of stellar parallax?

Accepted Answer

A)  spectral type and surface temperature 
B)  rotation period 
C)  apparent magnitude 
D)  distance from Earth 
A)  spectral type and surface temperature 
B)  rotation period 
C)  apparent magnitude 
D)  distance from Earth

Question 18

A particular star has an apparent magnitude of +12 and an absolute magnitude of +5. What is the distance to this star?

Accepted Answer

A)  125 pc 
B)  250 pc 
C)  125 ly 
D)  250 ly 
A)  125 pc 
B)  250 pc 
C)  125 ly 
D)  250 ly

Question 19

It was discovered that stars of the same temperature can include stars of different radii. The response to this finding was

Accepted Answer

A)  to refine the spectral classification scheme by introducing subheadings 0-9. 
B)  to revise the spectral classification to start with O rather than A. 
C)  to define the luminosity classes. 
D)  to invent the H-R diagram. 
A)  to refine the spectral classification scheme by introducing subheadings 0-9. 
B)  to revise the spectral classification to start with O rather than A. 
C)  to define the luminosity classes. 
D)  to invent the H-R diagram.

Question 20

A star of apparent magnitude +4.7 appears _____ than a star of apparent magnitude +4.8.

Accepted Answer

A)  brighter 
B)  either brighter or fainter, depending on the distance to the stars, 
C)  farther away 
D)  fainter 
A)  brighter 
B)  either brighter or fainter, depending on the distance to the stars, 
C)  farther away 
D)  fainter

From its position on the Hertzsprung-Russell diagram in Figure 12-7 in the text, what can an astronomer conclude about the star Mira compared with the Sun?

The technical designation for the bright star Regulus is $\alpha$ Leonis. This means that Regulus is

An eclipsing binary system consists of

A star with a surface temperature of 4000 K and a luminosity of about 10^-2 times that of the Sun is a member of which luminosity class? See Figure 12-10 from the text.

The surface temperature of a nearby star can be determined MOST precisely by measuring what parameters?

If an observer looks out at a clear night sky with the unaided eye, the faintest stars the observer can see have magnitudes around

If the intrinsically faintest stars in Earth's sky have absolute magnitudes of +17, how does their total energy output compare with that of the Sun, whose absolute magnitude is +4.8?

A star of apparent magnitude +3.5 appears _____ than a star of apparent magnitude +3.3.

Which one of these is NOT needed to compute a distance to a star by the spectroscopic parallax method?

A star has a surface temperature of 6000 K. Its spectrum registers a certain intensity in the green middle of the visible spectrum. Which of these must also be true of the star?

A star is 80 pc from the Sun. Its apparent motion against the background sky, that is, its stellar parallax, as a result of Earth's motion through 1 au is

A star of apparent magnitude +2.1 appears _____ than a star of apparent magnitude -1.2.

As an observer moves closer to a star, which two of its properties change?

Spectral types of stars (e.g., O, B, A, F, G, K, and M) uniquely define their

How far away is the nearest star beyond the Sun, in parsecs?

If a certain star shows a strong absorption spectrum in hydrogen Balmer lines, the surface temperature of the star is hot enough that

Which of these properties of a nearby star is determined by a measurement of stellar parallax?

A particular star has an apparent magnitude of +12 and an absolute magnitude of +5. What is the distance to this star?

It was discovered that stars of the same temperature can include stars of different radii. The response to this finding was

A star of apparent magnitude +4.7 appears _____ than a star of apparent magnitude +4.8.

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

From its position on the Hertzsprung-Russell diagram in Figure 12-7 in the text, what can an astronomer conclude about the star Mira compared with the Sun?

The technical designation for the bright star Regulus is α\alphaα Leonis. This means that Regulus is

An eclipsing binary system consists of

A star with a surface temperature of 4000 K and a luminosity of about 10-2 times that of the Sun is a member of which luminosity class? See Figure 12-10 from the text.

The surface temperature of a nearby star can be determined MOST precisely by measuring what parameters?

If an observer looks out at a clear night sky with the unaided eye, the faintest stars the observer can see have magnitudes around

If the intrinsically faintest stars in Earth's sky have absolute magnitudes of +17, how does their total energy output compare with that of the Sun, whose absolute magnitude is +4.8?

A star of apparent magnitude +3.5 appears _____ than a star of apparent magnitude +3.3.

Which one of these is NOT needed to compute a distance to a star by the spectroscopic parallax method?

A star has a surface temperature of 6000 K. Its spectrum registers a certain intensity in the green middle of the visible spectrum. Which of these must also be true of the star?

A star is 80 pc from the Sun. Its apparent motion against the background sky, that is, its stellar parallax, as a result of Earth's motion through 1 au is

A star of apparent magnitude +2.1 appears _____ than a star of apparent magnitude -1.2.

As an observer moves closer to a star, which two of its properties change?

Spectral types of stars (e.g., O, B, A, F, G, K, and M) uniquely define their

How far away is the nearest star beyond the Sun, in parsecs?

If a certain star shows a strong absorption spectrum in hydrogen Balmer lines, the surface temperature of the star is hot enough that

Which of these properties of a nearby star is determined by a measurement of stellar parallax?

A particular star has an apparent magnitude of +12 and an absolute magnitude of +5. What is the distance to this star?

It was discovered that stars of the same temperature can include stars of different radii. The response to this finding was

A star of apparent magnitude +4.7 appears _____ than a star of apparent magnitude +4.8.

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

The technical designation for the bright star Regulus is $\alpha$ Leonis. This means that Regulus is

A star with a surface temperature of 4000 K and a luminosity of about 10^-2 times that of the Sun is a member of which luminosity class? See Figure 12-10 from the text.