Question 1

Hydrogen and helium together account for what percentage of the total mass of all the matter in the universe?

Accepted Answer

A)  90% 
B)  98% 
C)  75% 
D)  about 50% 
A)  90% 
B)  98% 
C)  75% 
D)  about 50%

Question 2

Approximately how many planets are believed to exist in our Galaxy?

Accepted Answer

A)  eight 
B)  a few thousand 
C)  around a million 
D)  at least 100 billion 
A)  eight 
B)  a few thousand 
C)  around a million 
D)  at least 100 billion

Question 3

Astronomers believe that the stellar disk around the star Beta Pictoris contains a Jupiter-size planet. Why do they think this?

Accepted Answer

A)  The planet was imaged directly by the Hubble Space Telescope. 
B)  Effects of the intense magnetic field of this planet can be detected by powerful radio telescopes. 
C)  The gravitational effect of this planet has created an off-center disk of dust and gas around the star. 
D)  The planet causes a measurable decrease in the brightness of Beta Pictoris when it transits across its disk. 
A)  The planet was imaged directly by the Hubble Space Telescope. 
B)  Effects of the intense magnetic field of this planet can be detected by powerful radio telescopes. 
C)  The gravitational effect of this planet has created an off-center disk of dust and gas around the star. 
D)  The planet causes a measurable decrease in the brightness of Beta Pictoris when it transits across its disk.

Question 4

What was the first direct evidence that some other solar-type stars might have planets?

Accepted Answer

A)  faint pinpoints of light slowly circling some stars, as seen through the new 8- and 10-meter telescopes 
B)  slightly wavy path of a star through space, as if the star were being tugged by an orbiting planet 
C)  cyclic Doppler shift variations in the spectra of several stars 
D)  warped disks of dust and gas around some young stars 
A)  faint pinpoints of light slowly circling some stars, as seen through the new 8- and 10-meter telescopes 
B)  slightly wavy path of a star through space, as if the star were being tugged by an orbiting planet 
C)  cyclic Doppler shift variations in the spectra of several stars 
D)  warped disks of dust and gas around some young stars

Question 5

What is a planetary nebula?

Accepted Answer

A)  nebula of gas and dust around a giant planet 
B)  nebula of gas and dust around any planet 
C)  clouds of matter ejected into space by a dying star 
D)  result of a stellar explosion in which the entire star is blown apart 
A)  nebula of gas and dust around a giant planet 
B)  nebula of gas and dust around any planet 
C)  clouds of matter ejected into space by a dying star 
D)  result of a stellar explosion in which the entire star is blown apart

Question 6

What was the material from which the solar system formed?

Accepted Answer

A)  nebula made mostly of heavy elements but enriched in hydrogen and helium from supernova explosions 
B)  debris from the explosion of a massive star 
C)  nebula made entirely of hydrogen and helium gas 
D)  nebula made mostly of hydrogen and helium gas but enriched in heavier elements from planetary nebulae and supernova explosions 
A)  nebula made mostly of heavy elements but enriched in hydrogen and helium from supernova explosions 
B)  debris from the explosion of a massive star 
C)  nebula made entirely of hydrogen and helium gas 
D)  nebula made mostly of hydrogen and helium gas but enriched in heavier elements from planetary nebulae and supernova explosions

Question 7

Which of these is known to be a relatively common characteristic of exoplanet systems, in contrast to our own solar system?

Accepted Answer

A)  gas giants without any moons 
B)  eccentric orbits 
C)  terrestrial planets in the outer regions of exoplanet systems 
D)  impacts between exoplanets billions of years into the star system's lifetime 
A)  gas giants without any moons 
B)  eccentric orbits 
C)  terrestrial planets in the outer regions of exoplanet systems 
D)  impacts between exoplanets billions of years into the star system's lifetime

Question 8

Which of these provides a plausible method to measure the mass of an exoplanet?

Accepted Answer

A)  We use Newton's law of gravity, using the measured distance of the planet from its star and the planet's gravitational pull on the star. 
B)  We cannot make any firm estimate of the mass of an extrasolar planet with present technology. 
C)  We use spectra to measure the planet's temperature and photometry to measure its brightness. 
D)  We measure the planet's angular diameter and hence its size and then use spectra to find its composition and hence density. 
A)  We use Newton's law of gravity, using the measured distance of the planet from its star and the planet's gravitational pull on the star. 
B)  We cannot make any firm estimate of the mass of an extrasolar planet with present technology. 
C)  We use spectra to measure the planet's temperature and photometry to measure its brightness. 
D)  We measure the planet's angular diameter and hence its size and then use spectra to find its composition and hence density.

Question 9

What is the habitable zone?

Accepted Answer

A)  the range of orbital radii around a star in which liquid water can exist 
B)  the range of orbital radii around a star in which planets orbit the star 
C)  the range of orbital radii around the galactic center in which stars can host life 
D)  the range of atmospheric pressures in which life can evolve 
A)  the range of orbital radii around a star in which liquid water can exist 
B)  the range of orbital radii around a star in which planets orbit the star 
C)  the range of orbital radii around the galactic center in which stars can host life 
D)  the range of atmospheric pressures in which life can evolve

Question 10

Which of these processes are exoplanets forming in binary star systems more likely to undergo than those forming around single stars?

Accepted Answer

A)  escape the gravitational pull of the star(s) around which they form 
B)  undergo accretion 
C)  generate magnetic fields 
D)  form with very large orbital radii 
A)  escape the gravitational pull of the star(s) around which they form 
B)  undergo accretion 
C)  generate magnetic fields 
D)  form with very large orbital radii

Question 11

Suppose a dense core forms out of an interstellar cloud that is unusual because it does NOT rotate. How might the resulting protostar differ from the majority of other protostars?

Accepted Answer

A)  It would begin fusion at a higher internal temperature. 
B)  It would most likely lack a protoplanetary disk. 
C)  It would take much longer to form. 
D)  It would use a different set of fusion reactions to power itself. 
A)  It would begin fusion at a higher internal temperature. 
B)  It would most likely lack a protoplanetary disk. 
C)  It would take much longer to form. 
D)  It would use a different set of fusion reactions to power itself.

Question 12

The transit photometry method for detecting extrasolar planets around distant stars relies on variations in the star's

Accepted Answer

A)  brightness. 
B)  velocity. 
C)  position on the sky. 
D)  spectrum. 
A)  brightness. 
B)  velocity. 
C)  position on the sky. 
D)  spectrum.

Question 13

Which method of detecting exoplanets has revealed the MOST about the detailed structure and composition of exoplanets?

Accepted Answer

A)  radial velocity method 
B)  transit method 
C)  direct imaging 
D)  microlensing 
A)  radial velocity method 
B)  transit method 
C)  direct imaging 
D)  microlensing

Question 14

The majority of the elements beyond hydrogen and helium in the periodic table in the Sun and the solar system most likely originated in

Accepted Answer

A)  the center of our own Sun, through fusion and later ejection as solar wind. 
B)  chemical reactions in planetary atmospheres. 
C)  the original Big Bang of the universe. 
D)  fusion reactions in the centers of earlier stars. 
A)  the center of our own Sun, through fusion and later ejection as solar wind. 
B)  chemical reactions in planetary atmospheres. 
C)  the original Big Bang of the universe. 
D)  fusion reactions in the centers of earlier stars.

Question 15

The presence of dusty disks surrounding stars similar to the Sun was surprising because

Accepted Answer

A)  such systems could not have formed planets. 
B)  their composition differs so much from their stars. 
C)  their instruments were not thought to be powerful enough to make such a measurement. 
D)  gas and dust should be rapidly ejected into space by the radiation from a hot star. 
A)  such systems could not have formed planets. 
B)  their composition differs so much from their stars. 
C)  their instruments were not thought to be powerful enough to make such a measurement. 
D)  gas and dust should be rapidly ejected into space by the radiation from a hot star.

Question 16

Which of these methods for detecting exoplanets requires astronomers to take spectra of the stars around which the exoplanets orbit?

Accepted Answer

A)  astrometric method 
B)  radial velocity method 
C)  transit photometry method 
D)  transit timing method 
A)  astrometric method 
B)  radial velocity method 
C)  transit photometry method 
D)  transit timing method

Question 17

For an exoplanet to be detected via the astrometric method, it must

Accepted Answer

A)  orbit its star with a component of its motion parallel to the line of sight to from the star to Earth. 
B)  orbit its star with a component of its motion perpendicular to the line of sight to from the star to Earth. 
C)  have a low albedo. 
D)  have a high albedo. 
A)  orbit its star with a component of its motion parallel to the line of sight to from the star to Earth. 
B)  orbit its star with a component of its motion perpendicular to the line of sight to from the star to Earth. 
C)  have a low albedo. 
D)  have a high albedo.

Question 18

Exoplanets that orbit their stars on trajectories with very small semimajor axes are likely to

Accepted Answer

A)  have more moons than average exoplanets. 
B)  have rotation periods equal to their orbital periods. 
C)  have cool surface temperatures. 
D)  be captured from other stars. 
A)  have more moons than average exoplanets. 
B)  have rotation periods equal to their orbital periods. 
C)  have cool surface temperatures. 
D)  be captured from other stars.

Hydrogen and helium together account for what percentage of the total mass of all the matter in the universe?

Approximately how many planets are believed to exist in our Galaxy?

Astronomers believe that the stellar disk around the star Beta Pictoris contains a Jupiter-size planet. Why do they think this?

What was the first direct evidence that some other solar-type stars might have planets?

What is a planetary nebula?

What was the material from which the solar system formed?

Which of these is known to be a relatively common characteristic of exoplanet systems, in contrast to our own solar system?

Which of these provides a plausible method to measure the mass of an exoplanet?

What is the habitable zone?

Which of these processes are exoplanets forming in binary star systems more likely to undergo than those forming around single stars?

Suppose a dense core forms out of an interstellar cloud that is unusual because it does NOT rotate. How might the resulting protostar differ from the majority of other protostars?

The transit photometry method for detecting extrasolar planets around distant stars relies on variations in the star's

Which method of detecting exoplanets has revealed the MOST about the detailed structure and composition of exoplanets?

The majority of the elements beyond hydrogen and helium in the periodic table in the Sun and the solar system most likely originated in

The presence of dusty disks surrounding stars similar to the Sun was surprising because

Which of these methods for detecting exoplanets requires astronomers to take spectra of the stars around which the exoplanets orbit?

For an exoplanet to be detected via the astrometric method, it must

Exoplanets that orbit their stars on trajectories with very small semimajor axes are likely to

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

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

Characterizing Stars

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 5: Exoplanets and the Formation of Planetary Systems

Hydrogen and helium together account for what percentage of the total mass of all the matter in the universe?

Approximately how many planets are believed to exist in our Galaxy?

Astronomers believe that the stellar disk around the star Beta Pictoris contains a Jupiter-size planet. Why do they think this?

What was the first direct evidence that some other solar-type stars might have planets?

What is a planetary nebula?

What was the material from which the solar system formed?

Which of these is known to be a relatively common characteristic of exoplanet systems, in contrast to our own solar system?

Which of these provides a plausible method to measure the mass of an exoplanet?

What is the habitable zone?

Which of these processes are exoplanets forming in binary star systems more likely to undergo than those forming around single stars?

Suppose a dense core forms out of an interstellar cloud that is unusual because it does NOT rotate. How might the resulting protostar differ from the majority of other protostars?

The transit photometry method for detecting extrasolar planets around distant stars relies on variations in the star's

Which method of detecting exoplanets has revealed the MOST about the detailed structure and composition of exoplanets?

The majority of the elements beyond hydrogen and helium in the periodic table in the Sun and the solar system most likely originated in

The presence of dusty disks surrounding stars similar to the Sun was surprising because

Which of these methods for detecting exoplanets requires astronomers to take spectra of the stars around which the exoplanets orbit?

For an exoplanet to be detected via the astrometric method, it must

Exoplanets that orbit their stars on trajectories with very small semimajor axes are likely to

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

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

Characterizing Stars

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