Question 1

Only Earth- size terrestrial planets and Jupiter- size gas giants have been discovered in other planetary systems.

Accepted Answer

A) True 
 B)False

Question 2

You have observed the wobble in the velocity curves of two otherwise identical stars. Star A has a period of 6 months and Star B has a period of 1 year. What can you say about these stars?

Accepted Answer

A) Star A's planet is more massive than Star B's planet. 
B) It is impossible to say anything about the planets orbiting these stars. 
C) Star A's planet must be closer than Star B's planet. 
D) Star B must have a planet like Earth. 
A) Star A's planet is more massive than Star B's planet. 
B) It is impossible to say anything about the planets orbiting these stars. 
C) Star A's planet must be closer than Star B's planet. 
D) Star B must have a planet like Earth.

Question 3

Astronomers have discovered more extrasolar planets around other stars than the number of planets in our own Solar System.

Accepted Answer

A) True 
 B)False

Question 4

What is astrometry?

Accepted Answer

A) searching for planets around stars 
B) measuring distances to stars 
C) measuring the velocities of stars via the Doppler effect 
D) using metric units for distance (e.g., meters rather than light years) 
E) measuring the positions of stars on the sky 
A) searching for planets around stars 
B) measuring distances to stars 
C) measuring the velocities of stars via the Doppler effect 
D) using metric units for distance (e.g., meters rather than light years) 
E) measuring the positions of stars on the sky

Question 5

A planet's density can be determined if it is observed to periodically transit in front of its parent star causing eclipses.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following methods has led to the most discoveries of extrasolar planet candidates?

Accepted Answer

A) detecting the gravitational effect of an orbiting planet by looking for the Doppler shifts in the star's spectrum 
B) detecting the infrared light emitted by the planet 
C) detecting a planet ejected from a binary star system 
D) detecting the dip in measured brightness as the planet crosses our line of sight to the star 
E) detecting the shift of the star's position against the sky due to the planet's gravitational pull 
A) detecting the gravitational effect of an orbiting planet by looking for the Doppler shifts in the star's spectrum 
B) detecting the infrared light emitted by the planet 
C) detecting a planet ejected from a binary star system 
D) detecting the dip in measured brightness as the planet crosses our line of sight to the star 
E) detecting the shift of the star's position against the sky due to the planet's gravitational pull

Question 7

Which of the following methods uses the principle of orbital acceleration to detect planets around another star?

Accepted Answer

A) measuring change in the Doppler shifts of a star over the course of many nights 
B) measuring a single Doppler shift of a star, one time 
C) measuring the change of light of a star as the planet crosses in front of it 
D) taking a picture of the planet next to the star 
A) measuring change in the Doppler shifts of a star over the course of many nights 
B) measuring a single Doppler shift of a star, one time 
C) measuring the change of light of a star as the planet crosses in front of it 
D) taking a picture of the planet next to the star

Question 8

How can astronomers measure the composition of an extrasolar planet's atmosphere?

Accepted Answer

A) by measuring the composition of the host star; the planet must have formed from the same initial material 
B) by comparing spectra for when the planet is in transit or eclipse with spectra taken at other times 
C) by measuring how brightly the planet glows in infrared light 
D) by measuring the Doppler shift of the host star 
A) by measuring the composition of the host star; the planet must have formed from the same initial material 
B) by comparing spectra for when the planet is in transit or eclipse with spectra taken at other times 
C) by measuring how brightly the planet glows in infrared light 
D) by measuring the Doppler shift of the host star

Question 9

The transit method of planet detection works best for

Accepted Answer

A) big planets in face- on orbits around small stars. 
B) small planets in edge- on orbits around big stars. 
C) Earth- like planets in any orbit. 
D) small planets in face- on orbits around big stars. 
E) big planets in edge- on orbits around small stars. 
A) big planets in face- on orbits around small stars. 
B) small planets in edge- on orbits around big stars. 
C) Earth- like planets in any orbit. 
D) small planets in face- on orbits around big stars. 
E) big planets in edge- on orbits around small stars.

Question 10

What mechanism explains the presence of "hot Jupiters" around many other stars?

Accepted Answer

A) planetary migration caused by gravitational interactions between the planet and disk 
B) evaporation of the disk by the stellar wind removes gas that was holding the planet at a large radius 
C) rapid formation of the gas giant from evaporated rock and metal at the inner disk edge 
D) gravitational attraction by terrestrial planets that formed at small radii attract the giant planets inward 
A) planetary migration caused by gravitational interactions between the planet and disk 
B) evaporation of the disk by the stellar wind removes gas that was holding the planet at a large radius 
C) rapid formation of the gas giant from evaporated rock and metal at the inner disk edge 
D) gravitational attraction by terrestrial planets that formed at small radii attract the giant planets inward

Question 11

Which of the following methods has led to the most confirmed discoveries of massive planets orbiting near their parent stars?

Accepted Answer

A) detecting the shift of the star's position against the sky due to the planet's gravitational pull 
B) detecting a planet ejected from a binary star system 
C) detecting the gravitational effect of an orbiting planet by looking for the Doppler shifts in the star's spectrum 
D) detecting the infrared light emitted by the planet 
E) detecting the starlight reflected off the planet 
A) detecting the shift of the star's position against the sky due to the planet's gravitational pull 
B) detecting a planet ejected from a binary star system 
C) detecting the gravitational effect of an orbiting planet by looking for the Doppler shifts in the star's spectrum 
D) detecting the infrared light emitted by the planet 
E) detecting the starlight reflected off the planet

Question 12

The Doppler technique for planet detection has found Earth- like planets around nearby Sun- like stars

Accepted Answer

A) True 
 B)False

Question 13

The Doppler technique can be used to estimate the semimajor axis of a planet's orbit by

Accepted Answer

A) measuring the speed at which the star orbits the mutual center- of- mass of the star and planet, and using Newton's theory of gravity. 
B) measuring the amount by which the starlight is reduced when the planet transits. 
C) measuring the time it takes for the star's line- of- sight velocity to cycle from peak to peak, and using Newton's version of Kepler's Third law. 
D) measuring the asymmetries in the velocity curve. 
A) measuring the speed at which the star orbits the mutual center- of- mass of the star and planet, and using Newton's theory of gravity. 
B) measuring the amount by which the starlight is reduced when the planet transits. 
C) measuring the time it takes for the star's line- of- sight velocity to cycle from peak to peak, and using Newton's version of Kepler's Third law. 
D) measuring the asymmetries in the velocity curve.

Question 14

Which of the following statements is not true about the planets so far discovered around other stars?

Accepted Answer

A) Most of them are more massive than Earth. 
B) Photographs reveal that most of them have atmospheres much like that of Jupiter. 
C) Many of them orbit closer to their star than Jupiter orbits the Sun. 
D) Many of them have been discovered by observing Doppler shifts in the spectra of the stars they orbit. 
A) Most of them are more massive than Earth. 
B) Photographs reveal that most of them have atmospheres much like that of Jupiter. 
C) Many of them orbit closer to their star than Jupiter orbits the Sun. 
D) Many of them have been discovered by observing Doppler shifts in the spectra of the stars they orbit.

Question 15

The planet HAT- P- 32b has more than twice the radius of Jupiter, yet is only the same mass. It orbits its star more than a factor of ten closer than Mercury's orbit around the Sun. Which is the most plausible explanation for its large size?

Accepted Answer

A) The hydrogen and helium gas compressed under their own gravity. 
B) The mass measurement is mistaken, and it is actually about 10 times more massive than Jupiter. 
C) It is made of elements other than hydrogen and helium which do not compress under their own gravity. 
D) Planets that are close to a star are heated up and therefore larger. 
A) The hydrogen and helium gas compressed under their own gravity. 
B) The mass measurement is mistaken, and it is actually about 10 times more massive than Jupiter. 
C) It is made of elements other than hydrogen and helium which do not compress under their own gravity. 
D) Planets that are close to a star are heated up and therefore larger.

Question 16

You discover that a nearby star, very similar to the Sun, has a velocity curve that has a period of 6 months, induced by the orbit of a planet. You infer that

Accepted Answer

A) the planet's orbit radius is about 1 AU. 
B) the planet's orbit radius is less than 1 AU. 
C) the planet's orbit radius cannot be determined based on the information provided. 
D) the planet's orbit radius is greater than 1 AU. 
A) the planet's orbit radius is about 1 AU. 
B) the planet's orbit radius is less than 1 AU. 
C) the planet's orbit radius cannot be determined based on the information provided. 
D) the planet's orbit radius is greater than 1 AU.

Question 17

What is the chief difficulty in attempting to detect planets around other stars?

Accepted Answer

A) Even the largest planets are typically at least a factor of 10 times smaller than their host stars. 
B) Planets do not emit visible light. They are typically at least a billion times fainter than their host stars. 
C) Planets do not glow in the infrared, so infrared telescopes cannot be used to study them, either. 
D) A and B 
E) A, B, and C 
A) Even the largest planets are typically at least a factor of 10 times smaller than their host stars. 
B) Planets do not emit visible light. They are typically at least a billion times fainter than their host stars. 
C) Planets do not glow in the infrared, so infrared telescopes cannot be used to study them, either. 
D) A and B 
E) A, B, and C

Question 18

Kepler's Impact: In four years of operation, the Kepler satellite discovered nearly three times as many extrasolar planet candidates as had been discovered in the previous 15 years (since the first discovery of an extrasolar planet). Discuss how these observations changed our understanding of the population of planets and of planet formation.

Accepted Answer

May include: mention of finally being ab

Question 19

What must be true in order for astronomers to be able to use the Doppler technique to determine a planet's mass?

Accepted Answer

A) The planet's orbit must be seen nearly face on. 
B) The planet must have a very low mass. 
C) The planet must have a very eccentric orbit. 
D) The planet's orbit must be viewed nearly edge on. 
A) The planet's orbit must be seen nearly face on. 
B) The planet must have a very low mass. 
C) The planet must have a very eccentric orbit. 
D) The planet's orbit must be viewed nearly edge on.

Question 20

What are the two main differences between extrasolar planetary systems discovered to date and our Solar System?

Accepted Answer

A) Extrasolar planet orbits tend to be more eccentric and inclined than in our Solar System. 
B) Extrasolar planet orbits tend to be closer and more eccentric than in our Solar System. 
C) Extrasolar planets tend to be bigger and denser than Jupiter. 
D) Extrasolar planets tend to be more massive and dense than Jupiter. 
E) Extrasolar planet orbits tend to be closer and more circular than in our Solar System. 
A) Extrasolar planet orbits tend to be more eccentric and inclined than in our Solar System. 
B) Extrasolar planet orbits tend to be closer and more eccentric than in our Solar System. 
C) Extrasolar planets tend to be bigger and denser than Jupiter. 
D) Extrasolar planets tend to be more massive and dense than Jupiter. 
E) Extrasolar planet orbits tend to be closer and more circular than in our Solar System.

Only Earth- size terrestrial planets and Jupiter- size gas giants have been discovered in other planetary systems.

You have observed the wobble in the velocity curves of two otherwise identical stars. Star A has a period of 6 months and Star B has a period of 1 year. What can you say about these stars?

Astronomers have discovered more extrasolar planets around other stars than the number of planets in our own Solar System.

What is astrometry?

A planet's density can be determined if it is observed to periodically transit in front of its parent star causing eclipses.

Which of the following methods has led to the most discoveries of extrasolar planet candidates?

Which of the following methods uses the principle of orbital acceleration to detect planets around another star?

How can astronomers measure the composition of an extrasolar planet's atmosphere?

The transit method of planet detection works best for

What mechanism explains the presence of "hot Jupiters" around many other stars?

Which of the following methods has led to the most confirmed discoveries of massive planets orbiting near their parent stars?

The Doppler technique for planet detection has found Earth- like planets around nearby Sun- like stars

The Doppler technique can be used to estimate the semimajor axis of a planet's orbit by

Which of the following statements is not true about the planets so far discovered around other stars?

The planet HAT- P- 32b has more than twice the radius of Jupiter, yet is only the same mass. It orbits its star more than a factor of ten closer than Mercury's orbit around the Sun. Which is the most plausible explanation for its large size?

You discover that a nearby star, very similar to the Sun, has a velocity curve that has a period of 6 months, induced by the orbit of a planet. You infer that

What is the chief difficulty in attempting to detect planets around other stars?

What must be true in order for astronomers to be able to use the Doppler technique to determine a planet's mass?

What are the two main differences between extrasolar planetary systems discovered to date and our Solar System?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

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Exam 10: Other Planetary Systems: the New Science of Distant Worlds

Only Earth- size terrestrial planets and Jupiter- size gas giants have been discovered in other planetary systems.

You have observed the wobble in the velocity curves of two otherwise identical stars. Star A has a period of 6 months and Star B has a period of 1 year. What can you say about these stars?

Astronomers have discovered more extrasolar planets around other stars than the number of planets in our own Solar System.

What is astrometry?

A planet's density can be determined if it is observed to periodically transit in front of its parent star causing eclipses.

Which of the following methods has led to the most discoveries of extrasolar planet candidates?

Which of the following methods uses the principle of orbital acceleration to detect planets around another star?

How can astronomers measure the composition of an extrasolar planet's atmosphere?

The transit method of planet detection works best for

What mechanism explains the presence of "hot Jupiters" around many other stars?

Which of the following methods has led to the most confirmed discoveries of massive planets orbiting near their parent stars?

The Doppler technique for planet detection has found Earth- like planets around nearby Sun- like stars

The Doppler technique can be used to estimate the semimajor axis of a planet's orbit by

Which of the following statements is not true about the planets so far discovered around other stars?

The planet HAT- P- 32b has more than twice the radius of Jupiter, yet is only the same mass. It orbits its star more than a factor of ten closer than Mercury's orbit around the Sun. Which is the most plausible explanation for its large size?

You discover that a nearby star, very similar to the Sun, has a velocity curve that has a period of 6 months, induced by the orbit of a planet. You infer that

What is the chief difficulty in attempting to detect planets around other stars?

What must be true in order for astronomers to be able to use the Doppler technique to determine a planet's mass?

What are the two main differences between extrasolar planetary systems discovered to date and our Solar System?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters