Question 1

Which of the following types of stars are NOT suitable for advanced life?

Accepted Answer

A)  K-type 
B)  M-type 
C)  G-type 
D)  F-type

Question 2

If a star has an extrasolar planet, the shape of its radial velocity curve is related to the planet's

Accepted Answer

A)  orbital eccentricity 
B)  mass 
C)  radius 
D)  orbital period

Question 3

When high-mass stars dies, they explode as supernovae, leaving behind a

Accepted Answer

A)  white dwarf 
B)  neutron star or black hole 
C)  brown dwarf 
D)  red dwarf

Question 4

In an extrasolar planetary system containing a single planet, the parent star is measured to move about its center of mass every 24 years. Given this, what is the orbital period of the planet?

Accepted Answer

A)  48 years 
B)  12 years 
C)  24 years 
D)  this cannot be determined from this observation

Question 5

How can we explain the presence of extrasolar planetary systems with Jovian-sized planets at distances at which we normally find terrestrial planets?

Accepted Answer

A)  they are brown dwarfs that were captured by their parent stars 
B)  these are massive terrestrial planets that formed close to their parent stars 
C)  they are Jovian planets that were spun out from their rapidly spinning parent stars 
D)  the Jovian planets formed farther out and then migrated inward

Question 6

O-type stars

Accepted Answer

A)  have lifetimes long enough for advanced life to evolve 
B)  have lifetimes long enough for planets to form and for life to appear, but not long enough for advanced life 
C)  do not contain enough heavy elements to form planets 
D)  have lifetimes too short for planet formation

Question 7

Which of the following methods allows us to determine the size of an extrasolar planet around another star?

Accepted Answer

A)  detection of brightness changes in a star as a planet passes in front of it 
B)  detection of reflected starlight 
C)  regular changes in the positions of the parent stars with respect to more distant stars as they move across the sky 
D)  detection of Doppler shifts in the spectra of the parent stars

Question 8

The color of a star is a measure of its

Accepted Answer

A)  surface temperature 
B)  chemical composition 
C)  mass 
D)  size

Question 9

The results of statistical studies of the exoplanet systems discovered to date suggests that what proportion of stars are likely to have a planet less than half the size of the Earth and in an orbit within a star's habitable zone?

Accepted Answer

A)  10 to 20% 
B)  50% 
C)  much less than 10% 
D)  more than 90%

Question 10

Orphan planets are

Accepted Answer

A)  planets which have been flung out into interstellar space as a result of inward migration 
B)  moons of gas-giant planets which are in unstable orbits and escape becoming planets themselves 
C)  planets which have been gravitationally captured by other stars 
D)  bodies blasted from rocky planets by giant impacts becoming planets themselves

Question 11

The presence of elements heavier than helium in stars is very important because

Accepted Answer

A)  they provide the raw materials for the formation of planets and life 
B)  without them they could not form 
C)  they help stabilize their interiors 
D)  they are responsible for the fusion reactions at their centers

Question 12

What is the least common class of star in our galaxy?

Accepted Answer

A)  A-type 
B)  M-type 
C)  O-type 
D)  G-type

Question 13

If our solar system hadn't formed with a Jupiter-sized planet,

Accepted Answer

A)  the Sun would have been more massive, with a lifetime too short for life to evolve 
B)  the Earth would have never formed 
C)  the rate of impacts on the Earth may have been much higher, possibly preventing the appearance of life 
D)  the rate of impacts on the Earth may have been much lower, enabling the appearance of life much earlier

Question 14

In the Hertzprung-Russell diagram most stars are found

Accepted Answer

A)  on the main sequence 
B)  in the red giant region 
C)  in the white dwarf region 
D)  in the supergiant region

Question 15

Imagine we have a planet identical to Jupiter around another star, with the exception that its orbit is much closer. How would its size compare to Jupiter?

Accepted Answer

A)  it would be the same size 
B)  it would be larger 
C)  it would be much smaller 
D)  it would be slightly smaller

Question 16

Which of the following methods uses astrometry to detect extrasolar planets around other star systems?

Accepted Answer

A)  detection of Doppler shifts in the spectra of the parent stars 
B)  detection of reflected starlight 
C)  detection of brightness changes in a star as a planet passes in front of it 
D)  regular changes in the positions of the parent stars with respect to more distant stars as they move across the sky

Question 17

Stars are mostly made of

Accepted Answer

A)  hydrogen and helium 
B)  pure hydrogen 
C)  carbon, hydrogen, oxygen and nitrogen 
D)  an equal mixture of all elements

Question 18

The orbits of many extrasolar planets detected to date are

Accepted Answer

A)  parabolic 
B)  highly elliptical 
C)  perfectly circular 
D)  slightly elliptical

Question 19

Many of the known extrasolar planets orbit their stars

Accepted Answer

A)  more closely than Mercury orbits the Sun 
B)  at about the same distance as the Earth orbits the Sun 
C)  at about the same distance as the planet Jupiter orbits the Sun 
D)  much further than the distance the planet Jupiter orbits the Sun

Question 20

The most important property of a star which determines its evolution is its

Accepted Answer

A)  chemical composition 
B)  surface temperature 
C)  mass 
D)  radius

Exam 11: Extrasolar Planets: Their Nature and Potential Habitability