Astronomy 3

A Hertzsprung-Russell diagram (H-R Diagram) is a plot of ________

a. size versus brightness

b. size versus color

c. temperature versus color

d. color versus brightness

e. brightness versus temperature

e.

A blue star is ____ our Sun

a. colder and smaller than

b. hotter and smaller than

c. approximately the same temperature and size as

d. hotter and larger than

e. colder and larger than

d.

A main-sequence star like our sun is expected to be stable for approximately ____

a. 100 million years

b. 1 billion years

c. 100 billion years

d. 10 billion years

e. 10 million years

d.

A red star is ____ our Sun

a. hotter and larger than

b. colder and smaller than

c. hotter and smaller than

d. approximately the same temperature and size as

e. colder and larger than

b.

Balance for a main sequence star is achieved when ____

a. temperature matches the rate of nuclear fusion

b. gravitational collapse matches gas pressure

c. gas pressure matches temperature

d. nuclear fusion and fission occur at the same rate

e. all of the above

b.

Based on the observed red shifts in the spectral lines of distant galaxies astronomers conclude that ___

a. the universe is contracting

b. the universe is in a steady state

c. the universe is expanding

d. Earth is in the center of the universe

c.

Cool stars evolve much more quickly than do hot stars

a. True

b. False

b.

Dark Energy and Dark Matter are similar in that they both appear to be slowing the expansion of the universe

a. True

b. False

b.

Hubble’s law states that galaxies are receding from us at a speed that is proportional to their ____

a. mass

b. orientation

c. distance

d. volume

c.

On a Hertzprung-Russell Diagram, our Sun is classified as ____

a. a yellow giant

b. an average star

c. a mediocre star

d. a super star

e. a yellow dwarf

e.

Our galaxy is called the Milky Way

a. True

b. False

a.

Our galaxy is currently absorbing other galaxies

a. True

b. False

a.

Prior to the formation of the protostar, _____

a. the temperature of the cloud is greater than 10,000 K

b. nuclear fusion does not occur

c. the interstellar clouds are composed of equal amounts of hydrogen and helium

d. nuclear fusion converts hydrogen to helium

b.

Stars spend most of their life as giants

a. True

b. False

b.

Stars spend most of their life span as main-sequence stars

a. True

b. False

a.

The Milky Way is classified as an irregular galaxy

a. True

b. False

b.

The Sun belongs to this class of stars

a. red giant

b. black hole

c. white dwarf

d. main-sequence star

d.

The Sun is considered an average star

a. True

b. False

a.

The ____ means “the Sun in the making.”

a. protosun

b. nebular Sun

c. presun

d. sol

e. solar disk

a.

The bodies of our solar system began forming about 5 billion years ago from an enormous cloud of minute rocky fragments and gases

a. True

b. False

a.

The star’s color index is a quick way of determining its

a. luminosity

b. mass

c. temperature

d. density

e. composition

c.

In general, what can be said about type O and B stars compared to type K and M stars

a. They are hotter and older

b. They are hotter and younger

c. They are cooler and younger

d. They are cooler and older

e. They are neither hotter nor cooler, younger nor older

b.

The stars with masses comparable to our Sun’s, but sizes like the Earth are ____

a. white dwarfs

b. red main sequence stars

c. red giants

d. neutron stars

e. blue main sequence stars

a.

Main sequence stars are fusing hydrogen into helium in their cores

a. True

b. False

a.

About 90% of the star’s total life is spent on the main sequence

a. True

b. False

a.

A recurrent nova could eventually build up to a

a. Type II supernova

b. planetary nebula

c. Type I supernova

d. core composed of iron

e. helium flash

c.

A star is on the horizontal branch of the H-R diagram. Which statement is true?

a. It is burning only helium.

b. The star is about to return to the main sequence.

c. It is burning both hydrogen and helium.

d. The star is contracting.

e. It is about to experience the helium flash.

a.

The Galactic Year is the time for our solar system to orbit the Galaxy; it is about___

a. 15 million years

b. 225 million years

c. 4.5 billion years

d. 9.6 billion years

e. 13.5 billion years

b.

Our Sun lies about 30,000 light-years out from the Galactic Center

a. True

b. False

b.

Detailed measurements of the disk and central bulge region of our Galaxy suggest our Milky Way is a

a. quasar

b. very flat elliptical galaxy

c. very dusty irregular galaxy

d. normal spiral galaxy

e. barred spiral galaxy

e.

The densest stars are known to exist are ____

a. black holes

b. red dwarfs

c. white dwarfs

d. neutron stars

d.

The discovery that the universe appears to be expanding led to a widely accepted theory called

a. the Big Bang

b. Einstein’s Law

c. Hubble’s Law

d. the Doppler effect

a.

The first elements to form after “Big Bang” were ___

a. helium and hydrogen

b. hydrogen and iron

c. helium and oxygen

d. oxygen and hydrogen

e. oxygen and iron

a.

The hottest main sequence stars are also the most massive

a. True

b. False

a.

The measure of a star’s brightness is called its magnitude

a. True

b. False

a.

The most dense objects known are black holes

a. True

b. False

a.

What is the dominant factor in the life of a star

a. energy

b. size

c. gravity

d. composition

e. temperature

c.

What is the main factor that determines what will happen to a star after it consumes all of its nuclear fuel

a. mass

b. composition

c. size

d. velocity

e. temperature

a.

What was Hubble’s major contribution to Cosmology

a. He measured the size of the universe

b. He identified Cepheid Variable stars

c. He identified numerous new galaxies outside the Milky way

d. He proved the Big Bang Theory

e. He developed a new method for measuring the absolute magnitude of stars

c.

Which color stars have the coolest surface temperature

a. orange

b. yellow

c. red

d. blue

c.

Which color stars have the highest surface temperatures

a. red

b. blue

c. yellow

d. orange

b.

Which main-sequence stars are the least massive

a. orange

b. yellow

c. blue

d. red

d.

Which main-sequence stars are the most massive

a. yellow

b. blue

c. orange

d. red

b.

Which of the following events is not part of the history associated with the Big Bang Theory

a. About 13.7 billion years ago, our universe started with a huge explosion.

b. Our sun formed approximately 9 billion years after the universe formed.

c. Just before Big Bang occurred, there was only energy and disassociated electrons and protons.

d. The first matter formed 380,000 years after the formation of the universe.

c.

Which one of the objects listed below has the largest size

a. galactic clusters

b. galaxies

c. globular clusters

d. nebula

e. stars

a.

Most Stars within 16 light years of what type of stars

a. Main sequence red dwarf and not yellow stars

b. White Dwarfs

c. Red Giants

d. Blue Giants

a.

Of the 100 brightest stars, what type of star(s) are the most common

a. Red and Blue Giants

b. Yellow

c. Red Dwarfs

d. White Dwarfs

a.

TOI 700d is an exoplanet within it’s stars habital zone. Its’ star is M class tar with a .4 solar radius, what type of star is TOI 700?

a. Red Dwarf

b. Yellow

c. Red Gaint

d. White Dwarf

a.