ASTR 1020 exam 3

Which is the smallest object?

a neutron star

A galaxy has an H-alpha emission line observed at a wavelength 10 percent larger than the rest wavelength of H-alpha. What is the redshift of the galaxy?

0.1

What is in this image?

supernova remnant

Which is the most luminous?

quasar

Which contains the most stars?

a spiral galaxy

Galaxy A appears twice the angular size of Galaxy B. Assuming the two galaxies have the same physics size in kiloparsecs, which of the following is true?

Galaxy B is 2 times farther away than Galaxy A.

What fundamental particles make a Helium-3 atom?

5 up quarks, 4 down quarks, 2 electrons

What type of galaxy is in this image?

SBc

Which statement is FALSE?

planetary nebulae usually have black holes at their centers

Which statement is TRUE?

Stars form in molecular clouds, where temperatures are about 10 degrees Kelvin.

How tiny a spot is the Hubble Deep Field?

The size of President Roosevelt’s eye on a dime held at arm’s length.

Among these choices, what is the last thing that happens in the history of the Universe.

electrons join with nuclei to make atoms

If a galaxy had no dark matter, we would observe ...

the rotation velocity would decrease with increasing distance like the Keplerian curve in our Solar System

How many times bigger across is the Local Group of galaxies in which the Milky Way resides than the Milky Way is itself?

about 100 times bigger

Which one of the following is FALSE?

Galaxy collisions destroy most of the stars in the galaxies involved.

If a galaxy is moving away from us the wavelength of the light it emits will be ...

increased

If light takes 4 billion years to reach us from a distant galaxy, how many times farther away is the distant galaxy than the Andromeda galaxy, which is 2 million light years away?

2,000 times

The stars in the halo of our Milky Way Galaxy are

older and redder than those in the disk.

The supermassive black hole in the center of the Milky Way has a mass of

4 million solar masses

Which force has as its boson the photon?

electromagnetic

Which mysterious phenomena do scientists attribute to dark energy?

The increasing rate of expansion of the Universe.

Why can we NOT see back the whole way to the time the Big Bang expansion began?

The radiation scatters off matter frequently so the Universe is opaque.

What are the standard candles that were used to determine the Universe is accelerating?

Type Ia supernovae

An older star cluster ...

has a main sequence turnoff farther to the right on the H-R diagram.

Which of the following statements is TRUE?

Type II supernovae are produced by the death of a massive star.

A galaxy has an H-alpha emission line observed at a wavelength 10 percent larger than the rest wavelength of H-alpha. What is the redshift of the galaxy?

0.1

How many stars are there in the observable universe?

(based on the Hubble Deep Field Academy activity that you did)

10^22 stars

Why do you suppose the Cat's Eye Nebula has a certain symmetry?

Bipolar jets are creating matching shapes on both sides.

The largest stars are almost the size of ...

our Solar System

What populations of stars are relatively old?

Globular clusters

What type of radiation does dark matter emit?

none

What is in this image?

47 Tuc globular star cluster

What elements are in the Cassiopeia A supernova remnant?

all of the above

How many times bigger are galaxies than individual stars?

billions or trillions of times bigger

How do you measure the mass of the supermassive black hole at the center of the Milky Way?

look at the orbits of nearby stars and apply Kepler's third law

What is at the center of the Crab Nebula, that produces its magnetic field?

A neutron star

A supernova is expected in the Milky Way ...

once in every couple hundred years, and we are overdue.

How many "up" and "down" quarks make up a proton?

two ups and a down

What happens to the planets in a galaxy when that galaxy collides with

another galaxy?

Nothing, because the spaces between stellar systems in a galaxy is much larger than their size.

What is so special about Type Ia supernova that make them good distance indicators?

their luminosities are known.

What is the boson for the strong force?

gluon

The redshifts of galaxies are found to be larger ...

for galaxies that are farther away.

True or False? The primary evidence for an accelerating universe comes from observations of young stars in the Milky Way.

False; in order to measure accelerating expansion, we need to measure

the distances of objects billions of light-years away.

How did conditions differ from the present era when the Universe was young?

The young Universe was hotter, more dense, and smoother.

The supermassive black hole in the center of the Milky Way has a mass of ...

4 million solar masses

Which statement is TRUE?

Stars form in molecular clouds, where temperatures are about

10 degrees Kelvin.

Which component of the Milky Way galaxy is closest to its center?

bulge

A Helium-4 atom has a total of ...

2 protons, 2 neutrons, and 2 electrons

What is in this image?

Orion nebula star-forming region

What is the difference between an E0 and an E7 galaxy?

The E7 has an oval shape and the E0 is circular.

What parameters does Hubble's law relate to each other?

galaxy recession velocity and distance

Which force has as its boson the photon?

electromagnetic

What type of galaxy is this?

E5

If a galaxy had no dark matter, we would observe ...

the rotation velocity would decrease with increasing distance like

the Keplerian curve in our Solar System

Lerpz' original native habitat is ...

the surface of a neutron star

What are the differences between open star clusters and globular star clusters?

open clusters are less concentrated, younger, and have fewer stars

If light takes 4 billion years to reach us from a distant galaxy, how many times farther away is that distant galaxy than the Andromeda galaxy, which is 2 million light-years away?

2,000 times

What is in this image?

supernova remnant

The Large Magellanic Cloud and Small Magellanic Cloud are ...

satellite dwarf galaxies of the Milky Way.

in the symbol for the Hubble type of a galaxy, "SBc," the "B" denotes ...

the presence of a bar

Which contains more stars?

a spiral galaxy

Which does NOT provide evidence for dark matter?

The light that dark matter radiates.

In the earlier universe, ...

rregular galaxies were much more common than they are at the present

because galaxies were still in the process of being assembled.

Why can we not see back the whole way to the time when the Big Bang expansion began?

The radiation scatters off matter frequently so the Universe is opaque.

What gets left behind in the middle of a planetary nebula?

A white dwarf

Where are open clusters found in the Milky Way Galaxy?

in the disk

How have astronomers interpreted the unexpectedly fast rotation of galaxies?

There must be a lot of dark matter whose gravity can be felt but not seen.

Considering the contents of the Universe (including dark matter and dark energy),

Hydrogen and Helium account for ...

ess than 5 percent of the total.

Which of the following is TRUE?

At the time that the Big Bang expansion began, all matter and energy in

our observable universe was compressed into a single point of space.

The four forces are ...

gravity, electromagnetic, weak, and strong

What type of galaxy is this?

Irr

What do we mean when we say the universe becomes transparent at 300,000 years after the Big Bang?

electromagnetic radiation (light) can travel freely through the universe, so we can see to large distances

What is a quasar?

a very luminous source due to a black hole at the center of a galaxy that is quickly growing

Most of the stars in the Milky Way Galaxy are ...

red M-type stars

A nova is ...

a star that suddenly brightens and then goes to its normal brightness again, and then the process repeats.