Deck 18: The Stars

Question 1

Nuclear reactions in the sun's interior convert

A) hydrogen into helium.
B) helium into hydrogen.
C) carbon into nitrogen.
D) uranium into plutonium.

Answer 1

hydrogen into helium.

Question 2

The temperature of a star directly affects its

A) mass.
B) color.
C) composition.
D) age.

Answer 2

color.

Question 3

Advantages of a telescope in a spacecraft do not include

A) the absence of an atmosphere to affect light from space.
B) the absence of background radiation from the earth that may swamp faint signals from space.
C) less cost.
D) the ability to see the entire sky.

Answer 3

less cost.

Question 4

Stars seem to twinkle because of

A) variations in their brightnesses.
B) variations in their colors.
C) turbulent movements in their atmospheres.
D) turbulent movements in the earth's atmosphere.

Question 5

Because the spectra of most stars consist of dark lines on a bright background, these stars must

A) have cool interiors surrounded by hot atmospheres.
B) have hot interiors surrounded by cool atmospheres.
C) have hot interiors surrounded by hot atmospheres.
D) have cool interiors surrounded by cool atmospheres.

Question 6

The spectrum of a star can provide information of which one or more of the following?

A) the star's magnetic field
B) the star's temperature
C) the star's relative motion toward or away from us
D) the star's composition
E) All of the above

Question 7

Sunspots

A) are hotter than the rest of the solar surface.
B) are dark clouds floating in the solar atmosphere.
C) occur at random intervals.
D) are correlated with a number of terrestrial effects.

Question 8

The interior of the sun consists of

A) liquid hydrogen.
B) molecules.
C) neutral atoms.
D) ions.

Question 9

Sunspot activity does not affect

A) auroras.
B) the earth's magnetic field.
C) volcanic eruptions.
D) shortwave radio communications.

Question 10

A large modern astronomical telescope

A) is designed for high magnifications.
B) uses a single lens.
C) uses a single mirror.
D) uses a number of smaller mirrors.

Question 11

A star whose spectral lines are shifted toward the red end of the spectrum

A) has a magnetic field.
B) is moving toward us.
C) is moving away from us.
D) is moving across our line of sight.

Question 12

The source of the sun's energy is

A) radioactivity.
B) nuclear fission.
C) nuclear fusion.
D) combustion.

Question 13

Streams of protons and electrons from the sun do not affect

A) auroras.
B) the airglow of the night sky.
C) comet heads.
D) comet tails.

Question 14

The two chief elements in the sun are

A) hydrogen and helium.
B) hydrogen and oxygen.
C) oxygen and nitrogen.
D) carbon and iron.

Question 15

The sun has

A) no atmosphere.
B) an atmosphere just above its surface only.
C) an atmosphere that extends only as far as the earth.
D) an atmosphere that extends well out into the solar system.

Question 16

The sun is an)

A) unusually small star.
B) unusually large star.
C) unusually hot star.
D) rather ordinary star.

Question 17

The duration of the sunspot cycle is about

A) 27 days.
B) 6 months.
C) 3 years.
D) 11 years.

Question 18

The temperature of the sun's photosphere is about

A) 600 K.
B) 6000 K.
C) 14 million K.
D) 14 billion K.

Question 19

Which of the following can appear as disks with the help of a telescope?

A) planets
B) main-sequence stars
C) red giants
D) supernovas

Question 20

Advantages of large reflecting telescopes include their ability to

A) better resolve objects close together in the sky.
B) gather more light from faint objects.
C) be modified to correct for flickering images due to atmospheric turbulence.
D) All of these choices.

Question 21

White dwarfs

A) are young stars.
B) are old stars.
C) may be of any age.
D) are extremely rare.

Question 22

The majority of main-sequence stars are

A) blue.
B) white.
C) yellow.
D) red.

Question 23

The color of a relatively hot star is

A) white.
B) yellow.
C) blue.
D) red.

Question 24

Stars at the lower end of the main sequence have

A) high temperatures and large masses.
B) high temperatures and small masses.
C) low temperatures and large masses.
D) low temperatures and small masses.

Question 25

The sun will remain its present size and temperature

A) for a few thousand years longer.
B) for a few million years longer.
C) for a few billion years longer.
D) forever.

Question 26

In the HR diagram, most stars are

A) members of the main sequence.
B) red giants.
C) white dwarfs.
D) scattered at random.

Question 27

The size of a star can be found from its

A) temperature and mass.
B) temperature and brightness.
C) temperature and luminosity.
D) mass and apparent brightness.

Question 28

The star nearest to the sun is approximately

A) 1 light-minute away.
B) 4 light-years away.
C) 300 light-years away.
D) 4000 light-years away.

Question 29

Cepheid variable stars

A) are very bright, easily seen stars.
B) have luminosities related to their periods of variation.
C) have very short periods of variation.
D) all lie in the constellation Cepheus.

Question 30

A star must have a certain minimum mass in order that gravity squeeze its matter sufficiently to

A) hold it together as a single body.
B) produce a temperature high enough for it to glow.
C) produce a temperature high enough for nuclear reactions to start.
D) turn its interior into liquid hydrogen.

Question 31

Neutron stars are about

A) the size of a large house.
B) 20 km in diameter.
C) the size of the moon.
D) the size of Jupiter.

Question 32

The earth's magnetic field influences

A) comets.
B) meteoroids.
C) eclipses.
D) auroras.

Question 33

Red giant stars

A) are not very bright.
B) have relatively low surface temperatures.
C) represent the initial stage in a star's cycle.
D) are among the densest objects in the universe.

Question 34

The main sequence on the HR diagram includes

A) the sun.
B) white dwarfs.
C) red giants.
D) pulsars.

Question 35

The distance of a star from the earth can be found

A) only if it is part of a double-star system.
B) by comparing its luminosity and brightness.
C) from its color.
D) from its position in the HR diagram.

Question 36

White dwarf stars are not

A) comparable in size with the earth.
B) comparable in mass with the sun.
C) extremely hot.
D) extremely bright.

Question 37

In order to determine the mass of a star, it must be

A) part of the main sequence.
B) part of a binary-star system.
C) be a Cepheid variable.
D) be relatively close.

Question 38

Auroras consist of

A) colored clouds.
B) comet tails.
C) excited gases in the lower atmosphere.
D) excited gases in the upper atmosphere.

Question 39

There is a surprisingly small variation among stellar

A) temperatures.
B) diameters.
C) densities.
D) masses.

Question 40

The less the mass of a main-sequence star, the

A) lower its density.
B) cooler it is.
C) brighter it is.
D) shorter its lifetime.

Question 41

At the end of its period in the main sequence, a star whose mass is near that of the sun

A) breaks up into several smaller stars.
B) cools down into a white dwarf.
C) expands into a red giant.
D) explodes into a supernova.

Question 42

A gamma-ray burst is a short, intense flood of gamma rays

A) from the sun.
B) from the black hole at the center of our galaxy.
C) from a nearby neutron star.
D) that may have caused biological extinctions in the past.

Question 43

Brown dwarfs are

A) visible to the naked eye.
B) present in the solar system.
C) relatively rare.
D) relatively common.

Question 44

The smallest of the following celestial objects is

A) a white dwarf.
B) a neutron star.
C) a planetary nebula.
D) the earth.

Question 45

Black holes are the remnants of

A) stars with small masses.
B) stars with large masses.
C) white dwarfs.
D) black dwarfs.

Question 46

Brown dwarfs

A) are members of the main sequence.
B) are on the way to becoming white dwarfs.
C) do not have enough mass to become true stars.
D) are extremely rare.

Question 47

What keeps light from escaping from a black hole is its

A) strong electric field.
B) strong magnetic field.
C) strong gravitational field.
D) absorbing atmosphere.

Question 48

The least common of the following are

A) white dwarfs.
B) red dwarfs.
C) brown dwarfs.
D) black dwarfs.

Question 49

At the end of its period in the main sequence, a very heavy star

A) breaks up into several smaller stars.
B) cools down into a white dwarf.
C) expands into a red giant.
D) explodes into a supernova.

Question 50

Pulsars are unlikely to be

A) small in size.
B) in rapid rotation.
C) composed largely of neutrons.
D) members of the main sequence.

Question 51

Relatively few stars become

A) members of the main sequence.
B) red giants.
C) white dwarfs.
D) supernovas.

Question 52

The heaviest elements on the earth were produced in

A) the earth's interior.
B) the sun's interior.
C) supernova explosions.
D) black holes.

Question 53

A supernova explosion may leave behind a

A) neutron star.
B) white dwarf.
C) red dwarf.
D) red giant.