Question 1

Extrasolar planets have NOT been found:

Accepted Answer

A)  around burned-out remnants of stars. 
B)  around stars in the disks of other galaxies. 
C)  in globular clusters. 
D)  around stars in the disk of our Galaxy. 
A)  around burned-out remnants of stars. 
B)  around stars in the disks of other galaxies. 
C)  in globular clusters. 
D)  around stars in the disk of our Galaxy. B

Question 2

An asteroid belt has been discovered around the star Zeta Leporis.How were these comets discovered?

Accepted Answer

A)  The asteroids were imaged directly by the Hubble Space Telescope. 
B)  A ring of hot dust was discovered around the star by spectroscopy, and collisions among asteroids were inferred as the cause. 
C)  The gravitational effects of the asteroids have created an off-center disk of dust and gas around the star. 
D)  The gravitational effects of the asteroids cause the star to wobble slightly in its proper motion. 
A)  The asteroids were imaged directly by the Hubble Space Telescope. 
B)  A ring of hot dust was discovered around the star by spectroscopy, and collisions among asteroids were inferred as the cause. 
C)  The gravitational effects of the asteroids have created an off-center disk of dust and gas around the star. 
D)  The gravitational effects of the asteroids cause the star to wobble slightly in its proper motion. B

Question 3

Which characteristic in extrasolar planets is one for which we look as a likely characteristic of a life-bearing planet?

Accepted Answer

A)  large size (Jupiter-sized) 
B)  an oxygen-rich atmosphere 
C)  an orbit around a star much more massive than the Sun 
D)  a highly eccentric planetary orbit 
A)  large size (Jupiter-sized) 
B)  an oxygen-rich atmosphere 
C)  an orbit around a star much more massive than the Sun 
D)  a highly eccentric planetary orbit B

Question 4

Calculations suggest that the number of free-floating planets in the Milky Way Galaxy is:

Accepted Answer

A)  only a relative few since they must occur very rarely. 
B)  a few thousand at most. 
C)  around a billion. 
D)  more numerous than the stars. 
A)  only a relative few since they must occur very rarely. 
B)  a few thousand at most. 
C)  around a billion. 
D)  more numerous than the stars.

Question 5

Observers in a distant solar system are watching our Sun and using the radial-velocity method to try to determine whether the Sun has planets.Because of the gravitational pull of Jupiter,the observers see the Sun's spectrum slowly redshift and then blueshift by a tiny amount.How long must they observe to see a full cycle?

Accepted Answer

A)  25 days 
B)  1 year 
C)  almost 12 years 
D)  It depends on how far away the observers are. 
A)  25 days 
B)  1 year 
C)  almost 12 years 
D)  It depends on how far away the observers are.

Question 6

In searches for planets orbiting stars other than the Sun,what is the astrometric method?

Accepted Answer

A)  searching for tiny "bumps" on images of a star, due to the light from a planet located close to the star 
B)  searching for tiny displacements of the infrared image of a star compared with its optical image, caused by the presence of planets that are cool and thus emitting primarily in the infrared 
C)  searching for tiny wobbles in the position of a star, due to the gravitational pull of a planet orbiting around it 
D)  searching for tiny wobbles in the positions of absorption lines in a star's spectrum, caused by radial-velocity variations of the star as the result of a planet orbiting around it 
A)  searching for tiny "bumps" on images of a star, due to the light from a planet located close to the star 
B)  searching for tiny displacements of the infrared image of a star compared with its optical image, caused by the presence of planets that are cool and thus emitting primarily in the infrared 
C)  searching for tiny wobbles in the position of a star, due to the gravitational pull of a planet orbiting around it 
D)  searching for tiny wobbles in the positions of absorption lines in a star's spectrum, caused by radial-velocity variations of the star as the result of a planet orbiting around it

Question 7

A particular star shows spectral lines of the lithium isotope ⁶Li.What conclusion do astronomers draw from this observation?

Accepted Answer

A)  The star has vaporized one of its planets that spiraled in too close to the star because the star's own ⁶Li was destroyed by nuclear reactions long ago. 
B)  The star has not yet begun nuclear reactions in its core because these reactions destroy ⁶Li. 
C)  Planets must be orbiting around the star because only planets show ⁶Li spectral lines. 
D)  The star is composed of pristine (unmodified) material from the Big Bang because ⁶Li has been destroyed in material that has been processed in stars and expelled back into space. 
A)  The star has vaporized one of its planets that spiraled in too close to the star because the star's own ⁶Li was destroyed by nuclear reactions long ago. 
B)  The star has not yet begun nuclear reactions in its core because these reactions destroy ⁶Li. 
C)  Planets must be orbiting around the star because only planets show ⁶Li spectral lines. 
D)  The star is composed of pristine (unmodified) material from the Big Bang because ⁶Li has been destroyed in material that has been processed in stars and expelled back into space.

Question 8

Of the perhaps 200 billion stars estimated to exist in the Galaxy,about how many are believed to be have Earth-like planets orbiting them close to the star?

Accepted Answer

A)  almost none 
B)  a few million 
C)  perhaps 35 billion 
D)  almost all of them 
A)  almost none 
B)  a few million 
C)  perhaps 35 billion 
D)  almost all of them

Question 9

Comets been discovered around the star Beta Pictoris.How was this belt discovered?

Accepted Answer

A)  The comets were imaged directly by the Hubble Space Telescope when they are close to the star and glowing brightly. 
B)  Comets travel far from the star, enough so that they can be imaged outside its glare. 
C)  The comets emit gas when they pass close to the star. 
D)  The gravitational effects of the comets cause the star to wobble slightly in its proper motion. 
A)  The comets were imaged directly by the Hubble Space Telescope when they are close to the star and glowing brightly. 
B)  Comets travel far from the star, enough so that they can be imaged outside its glare. 
C)  The comets emit gas when they pass close to the star. 
D)  The gravitational effects of the comets cause the star to wobble slightly in its proper motion.

Question 10

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 11

The atmosphere of the gas-giant planet HD 209458b is believed to contain hydrogen,sodium,oxygen,carbon,and carbon monoxide.Where does this information come from?

Accepted Answer

A)  All known gas giants contain these molecules, so it is assumed that this one does also. 
B)  Light shines through the planet's atmosphere when it passes in front of its star, so a spectrum can be taken. 
C)  As the planet orbits its star, it leaves a trail of atmosphere behind. This can be analyzed spectroscopically. 
D)  Gas giants always have the same composition as their stars, and we have measured the spectrum of HD 209458. 
A)  All known gas giants contain these molecules, so it is assumed that this one does also. 
B)  Light shines through the planet's atmosphere when it passes in front of its star, so a spectrum can be taken. 
C)  As the planet orbits its star, it leaves a trail of atmosphere behind. This can be analyzed spectroscopically. 
D)  Gas giants always have the same composition as their stars, and we have measured the spectrum of HD 209458.

Question 12

In order for an exoplanet to be capable of sustaining life,all of the following situations would have to be true EXCEPT ONE.Which is the exception?

Accepted Answer

A)  The planet would have to be far enough from its star that liquid water would not boil away. 
B)  The planet would have to be close enough to its star that liquid water would not be permanently frozen. 
C)  The planet would have to revolve around a Sun-like star. 
D)  The planet would have to be in a solar system containing a giant planet in a highly eccentric orbit. 
A)  The planet would have to be far enough from its star that liquid water would not boil away. 
B)  The planet would have to be close enough to its star that liquid water would not be permanently frozen. 
C)  The planet would have to revolve around a Sun-like star. 
D)  The planet would have to be in a solar system containing a giant planet in a highly eccentric orbit.

Question 13

Exoplanets were first observed in:

Accepted Answer

A)  1810. 
B)  1931. 
C)  1992. 
D)  2012. 
A)  1810. 
B)  1931. 
C)  1992. 
D)  2012.

Question 14

We have begun to observe exoplanets not orbiting stars.How do we think they were formed?

Accepted Answer

A)  They were formed around stars that died, cooled, and are no longer visible. 
B)  They were formed in dust clouds, as are stars, but in this case the star did not form. 
C)  They formed from free-floating planetesimals that had escaped from various solar systems. 
D)  They formed normally in solar systems but then were forced out by the gravitational influences of other masses. 
A)  They were formed around stars that died, cooled, and are no longer visible. 
B)  They were formed in dust clouds, as are stars, but in this case the star did not form. 
C)  They formed from free-floating planetesimals that had escaped from various solar systems. 
D)  They formed normally in solar systems but then were forced out by the gravitational influences of other masses.

Question 15

The largest exoplanet discovered thus far has a radius about how many times Earth's radius?

Accepted Answer

A)  2 
B)  10 
C)  25 
D)  800 
A)  2 
B)  10 
C)  25 
D)  800

Question 16

During the 1860s,a hypothetical planet named Vulcan,in a solar orbit closer to the Sun than Mercury,was proposed as the cause of abnormalities in Mercury's orbit.Much of the 1860s and 1870s was spent studying the solar disk waiting for Vulcan to cross.Vulcan never appeared (but we learned a great deal about sunspots!).This technique is like which exoplanet-discovery technique?

Accepted Answer

A)  distorted protoplanetary disks 
B)  the transit method 
C)  the radial-velocity method 
D)  the astrometric method 
A)  distorted protoplanetary disks 
B)  the transit method 
C)  the radial-velocity method 
D)  the astrometric method

Question 17

The age of the oldest extrasolar planet is estimated to be about:

Accepted Answer

A)  half a million years. 
B)  4.5 billion years, similar to Earth's age. 
C)  only a few thousand years. 
D)  13 billion years. 
A)  half a million years. 
B)  4.5 billion years, similar to Earth's age. 
C)  only a few thousand years. 
D)  13 billion years.

Question 18

It is believed that the stellar disk around the star Beta Pictoris contains a Jupiter-size planet.What is the reason behind this belief?

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 19

What type of search technique has discovered the largest number of systems with multiple exoplanets?

Accepted Answer

A)  distorted protoplanetary disks 
B)  the transit method 
C)  the radial-velocity method 
D)  the astrometric method 
A)  distorted protoplanetary disks 
B)  the transit method 
C)  the radial-velocity method 
D)  the astrometric method

Question 20

What is surprising about the extrasolar planets that have so far been discovered?

Accepted Answer

A)  More than half of the extrasolar planets have strong lines of molecular oxygen in their spectra, a possible indication of life on these planets. 
B)  The majority of the extrasolar planets rotate much faster than the planets in our solar system. 
C)  Many of the extrasolar planets are giant planets like Jupiter, orbiting at distances characteristic of terrestrial planets like Earth, where giant planets cannot form. 
D)  Many of the extrasolar planets are terrestrial planets like Earth, orbiting at distances characteristic of giant planets like Jupiter, where terrestrial planets cannot form. 
A)  More than half of the extrasolar planets have strong lines of molecular oxygen in their spectra, a possible indication of life on these planets. 
B)  The majority of the extrasolar planets rotate much faster than the planets in our solar system. 
C)  Many of the extrasolar planets are giant planets like Jupiter, orbiting at distances characteristic of terrestrial planets like Earth, where giant planets cannot form. 
D)  Many of the extrasolar planets are terrestrial planets like Earth, orbiting at distances characteristic of giant planets like Jupiter, where terrestrial planets cannot form.

Extrasolar planets have NOT been found:

An asteroid belt has been discovered around the star Zeta Leporis.How were these comets discovered?

Which characteristic in extrasolar planets is one for which we look as a likely characteristic of a life-bearing planet?

Calculations suggest that the number of free-floating planets in the Milky Way Galaxy is:

In searches for planets orbiting stars other than the Sun,what is the astrometric method?

A particular star shows spectral lines of the lithium isotope ⁶Li.What conclusion do astronomers draw from this observation?

Of the perhaps 200 billion stars estimated to exist in the Galaxy,about how many are believed to be have Earth-like planets orbiting them close to the star?

Comets been discovered around the star Beta Pictoris.How was this belt discovered?

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

The atmosphere of the gas-giant planet HD 209458b is believed to contain hydrogen,sodium,oxygen,carbon,and carbon monoxide.Where does this information come from?

In order for an exoplanet to be capable of sustaining life,all of the following situations would have to be true EXCEPT ONE.Which is the exception?

Exoplanets were first observed in:

We have begun to observe exoplanets not orbiting stars.How do we think they were formed?

The largest exoplanet discovered thus far has a radius about how many times Earth's radius?

The age of the oldest extrasolar planet is estimated to be about:

It is believed that the stellar disk around the star Beta Pictoris contains a Jupiter-size planet.What is the reason behind this belief?

What type of search technique has discovered the largest number of systems with multiple exoplanets?

What is surprising about the extrasolar planets that have so far been discovered?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters

Exam 5: Exoplanets

Extrasolar planets have NOT been found:

An asteroid belt has been discovered around the star Zeta Leporis.How were these comets discovered?

Which characteristic in extrasolar planets is one for which we look as a likely characteristic of a life-bearing planet?

Calculations suggest that the number of free-floating planets in the Milky Way Galaxy is:

In searches for planets orbiting stars other than the Sun,what is the astrometric method?

A particular star shows spectral lines of the lithium isotope ⁶Li.What conclusion do astronomers draw from this observation?

Of the perhaps 200 billion stars estimated to exist in the Galaxy,about how many are believed to be have Earth-like planets orbiting them close to the star?

Comets been discovered around the star Beta Pictoris.How was this belt discovered?

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

The atmosphere of the gas-giant planet HD 209458b is believed to contain hydrogen,sodium,oxygen,carbon,and carbon monoxide.Where does this information come from?

In order for an exoplanet to be capable of sustaining life,all of the following situations would have to be true EXCEPT ONE.Which is the exception?

Exoplanets were first observed in:

We have begun to observe exoplanets not orbiting stars.How do we think they were formed?

The largest exoplanet discovered thus far has a radius about how many times Earth's radius?

The age of the oldest extrasolar planet is estimated to be about:

It is believed that the stellar disk around the star Beta Pictoris contains a Jupiter-size planet.What is the reason behind this belief?

What type of search technique has discovered the largest number of systems with multiple exoplanets?

What is surprising about the extrasolar planets that have so far been discovered?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters