Download ASTR 1020 FINAL EXAM STUDY GUIDE

ASTR 1020 FINAL EXAM STUDY GUIDE
Chapter S2
1) What are the two basic premises for the special theory of relativity?
2) Describe the predictions made by Einstein’s special theory of relativity?
3) In relativity, define when two people share the same frame of reference.
Chapter S3
1) What does the equivalence principle say?
2) Define the conditions under which you will feel weightless according to general relativity.
3) Which of the following is false:
a. The speed of light in a vacuum is constant.
b. Nothing can move faster than the speed of light.
c. Observers in different references frames measure the same speed of light.
d. The absoluteness of the speed of light is an experimentally verified fact.
e. The speed of light slows down near a black hole.
Chapter S4
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What does the field of quantum mechanics study?
What is the primary purpose of a particle accelerator?
What is the characteristic which distinguishes fermions from bosons?
What law of nature explains why electrons must arrange themselves in atoms with no more
than two per energy level, thus making chemistry possible?
Chapter 14
1) As no spacecraft has ventured into the interior of the Sun, what evidence then do we have to
support our current ideas about the solar interior?
2) What processes are involved in the sunspot cycle?
3) What are coronal holes?
4) Which forms of light are primarily emitted from the chromosphere and the corona?
5) What is a possible solution to the solar neutrino problem?
6) Why must the Sun’s rate of fusion gradually rise over billions of years?
7) What happens to the positron generated in the first stage of the proton-proton chain?
8) Fusion converts hydrogen into what specifically at the center of the Sun? (There is more than
one answer to this question)
9) Why do sunspots appear dark in pictures of the Sun?
Chapter 15
1) What do we mean by the main-sequence turnoff point of a star cluster, and what does it tell us?
2) What is a white dwarf?
3) How is the lifetime of a star related to its mass?
4) What do the axes on a Hertzsprung-Russel (H-R) diagram represent?
5) What is the primary method astronomers use to determine the mass of a star?
6) Star A has an apparent magnitude of 3 and Star B has an apparent magnitude of 5. Which star is
brighter in our sky?
7) If Star A is closer to us than Star B, then Star A’s parallax angle is larger or smaller than Star B?
8) What is the common trait of all main-sequence stars?
9) On an H-R diagram, what can be said concerning stellar masses?
Chapter 16
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Where would a brown dwarf be located on an H-R diagram?
What prevents a brown dwarf from undergoing nuclear fusion?
What is the smallest mass a newborn star can have?
What happens to the surface temperature and luminosity when a protostar radiatively
contracts?
When does a star become a main-sequence star?
What happens to the rotation of a molecular cloud as it collapses to form a star?
When is thermal energy trapped in the dense center of a cloud?
Why do we think the first generation of stars would be different from stars born today?
What properties of a molecular cloud help to counteract gravitational contraction?
Chapter 17
1) Why do scientists think that our Solar System must have formed sometime after nearby
supernova explosions?
2) Why is Supernova 1987A particularly important to astronomers?
3) After a supernova event, what is left behind?
4) Describe the different stages of nuclear burning (i.e. first-stage hydrogen burning, second-stage
helium burning, etc.) in a massive star.
5) What is the CNO cycle?
6) Where are most interstellar dust grains produced?
7) What is a planetary nebula?
8) What happens to the core of a star after a planetary nebula occurs?
9) Why does a star grow larger after it exhausts its core hydrogen?
Chapter 18
1) What observational evidence do scientists have of the existence of black holes?
2) Why do astronomers consider gamma-ray bursts to be one of the greatest mysteries in
astronomy?
3) How do we know the gamma-ray bursts do not come from neutron stars with accretion disks?
4) What do we mean by the singularity of a black hole?
5) When we see X-rays from an accretion disk in a binary system, we can’t immediately tell
whether the accretion disk surrounds a neutron star or a black hole. What phenomenon occurs
in a neutron star system, but not in the black hole system?
6) If you replaced the Sun with a black hole of the same mass, what would happen to the Earth?
7) How do we know that pulsars are neutron stars?
8) Observationally, how can we tell the difference between a white dwarf supernova and a
massive-star supernova?
9) How does the gravity of an object affect the light emitted from that object?
Chapter 19
1) What evidence do we have that the spheroidal population of stars are older than other stars in
the galaxy?
2) In each wavelength, what is the primary structure that we see when we look toward the Galactic
center?
3) What evidence suggests that the protogalactic cloud that formed the Milky Way resulted from
several collisions among smaller clouds?
4) Describe the characteristics of a globular cluster (e.g. size, color, age, etc.).
5) Describe the differences between the stars in the disk with the stars in the halo.
6) Suppose you read somewhere that 10 percent of the matter in the Milky Way is in the form of
dust grains. Should you be surprised? If so, why?
7) What produces the 21-cm line that we use to map out the Milky Way Galaxy?
8) What is the galactic fountain model?
9) What is a superbubble?
Chapter 20
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What does the equivalent of a H-R diagram for galaxies, plotting luminosity versus color show?
Based on current estimates of the value of Hubble’s constant, how old is the universe?
List the different rungs of the cosmic distance ladder in order of distance measured.
What is a standard candle?
List the reasons white dwarf supernova are good standard candles for distance measurements.
List the characteristics of each major type of galaxy (e.g. elliptical, spiral, irregular)
How does a lenticular galaxy differ from a normal spiral galaxy?
Determine the size and luminosity relation between large and small galaxies.
List the various components of a spiral galaxy.
Chapter 21
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What is a quasar?
Describe the evidence that quasars were more common in the early stages of the universe.
How do you know that there are intergalactic clouds between a distant quasar and us?
Describe the evidence supporting the conclusion that active galactic nuclei are powered by
accretion disks around massive black holes.
What is a galactic wind?
What evidence supports the idea that a collision between two spiral galaxies might lead to the
creation of a single elliptical galaxy?
Why is a dense cloud more likely to produce an elliptical galaxy than a spiral galaxy?
List the two main assumptions of theoretical models of galaxy evolution.
How do observations of distant galaxies help us learn about galaxy evolution?
Chapter 22
1) How is the time prior to the Planck time referred to by astronomers?
2) You are feeling like spaghetti. Although normally only about 2 meters tall, you are now about 25
meters long. As you look overhead, you see things are moving pretty quickly in the universe –
but that lasts only for a brief instant and then all contact with the universe is lost. Where are
you?
3) Describe the observational evidence supporting the Big Bang theory.
4) You are in a very hot, very dense place. You are surrounded by protons and neutrons, some
rapidly fusing into helium. You notice that your surroundings are cooling and rapidly dropping in
density. Within about 3 minutes, the fusion reactions stop. Where are you?
5) You find yourself in a place that looks perfectly symmetrical. There is no way to distinguish one
place from another, and all forces are one. With this perfect symmetry, there is no obvious way
to define the flow of time. Where are you?
6) What is postulated to have caused a sudden inflation of the early universe?
7) Where does helium originate?
8) Where do the photons in the cosmic background radiation originate?
9) Why did the era of nuclei end when the universe was about 300,000 years old?
Chapter 23
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Why do we call dark matter “dark”?
What is meant by “dark energy”?
How do we know that there is much more mass in the halo of our galaxy than in the disk?
What evidence suggests that the Milky Way contains dark matter?
When we see that a spectral line of a galaxy is broadened, that is, spanning a range of
wavelengths, what can we conclude about the stars in this galaxy?
Which method to determine the mass of a galactic cluster does not depend on Newton’s laws of
gravity?
Describe the characteristics of rich galaxy clusters.
Describe the various pieces of evidence for dark matter.
What does measuring the amount of deuterium in the universe allow us to set a limit on?