Download Study Guide for 3RD Astronomy Exam

Study Guide for 2nd Astronomy Exam
The successful student will be able to…
Unit 51: The Sun, Our Star
List or identify the vital statistics of the Sun (51.1 and class
handout).
Describe the Sun in terms of a 2-layer model (51.2 and
class handout).
Unit 51: The Suns Source of Power
Describe, in an essay, how the Sun produces energy.
Unit 54: Surveying the Stars (54.2 & 54.3)
Describe or identify how a parsec is defined.
Convert stellar distances between parsecs and light years.
Use the stellar parallax formula
D pc 
1
p"
to solve
problems
List or identify the definition of the stellar motion terms.
Interpret stellar apparent magnitudes and their relationship
to brightness.
Interpret stellar absolute magnitudes and their relationship
to luminosity.
Solve problems relating to the relative brightness or
luminosity of two stars given their m or M values.
Unit 56: The Temperatures and Compositions of Stars
(56.2 & 56.5)
Apply Wien’s Law
T
2.9  10 6 K  nm
Max
to a star.
Determine the hottest and coolest stars from a list of stars
with their spectral types.
Practice Exercise
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Write an outline summarizing the net p-p chain, defining symbols and discussing the
origin of each. Discuss thermalization and the rate of mass loss.
Write the definition of a parsec.
Convert 500 pc into ly and 500 ly into pc.
Verify that a star with a parallax 0.00229” is at a distance of 2,600 ly.
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Define Proper Motion and give an example of it. Define the space velocity.
Answer the questions on the Canis Major constellation sheet on Hot Tips
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How many times brighter is a star with m = -1 compared to a star with m = 6?
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How many time more luminous than the Sun is a star with M = -8?
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At what wavelength will a F0 star (7,200 K) emit its
maximum energy? What part of the EM spectrum is this
in?
What is the approximate Spectral Type of the star whose
spectrum is shown to the right? You’ll need to use the
appendix in the text on Properties of Main Sequence
Stars.
Complete the Take Home Quiz on Hot Tips under Week 9
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State or identify a characteristic temperature for an O star, a
G2 star and an M star.
Unit 57: The Masses of Stars (57.1, 57.2)
Describe or identify types of binary stars.
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State or identify what additional information can be
obtained from and eclipsing binaries besides the combined
mass of the stars.
Determine the combined mass of a binary star system using
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a3
m A  mB  AU2
Pyr
List the radius, volume and mass of the Sun compared to the Earth. List the surface and
core temperatures of the Sun.
List the defining property of the Core and the characteristics of the core and envelope.
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Create a pictorial representation of the four types of binary stars using hypothetical
spectral types and distances.
Write the properties of the stars in an eclipsing binary star system that can be
determined.
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Two stars orbit each other with an orbital semimajor axis of 20 AU and an orbital
period of 30 years. What is their combined mass? If they are both main sequence stars,
what spectral types can they not be? You’ll need to use the appendix in the text on
Properties of Main Sequence Stars.
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Draw, by hand, a blank HR diagram that is properly labeled and includes the Main
Sequence.
Complete the Take Home Quiz on Hot Tips under Week 9
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Complete this table.
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Write down the physical composition and dimensional characteristics of a GMC.
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Describe why proto-stars are hot.
How does the initial mass function or birth function explain why there are so many K
and M main sequence stars.
List the upper and lower stellar mass limits with the reason for these limits.
Create a list of steps describing how a GMC transforms into an Open Cluster, include
OB association, HII region in the list
Use the Astronomy Picture of the Day “Search” feature to see examples of these
objects.
Unit 58: The Sizes of Stars (58.3)
Solve problems with the Stefan-Boltzmann Law
L  4R 2  T 4 similar to HW problems.
Unit 59: The H-R Diagram (59.1, 59.2, 59.3)
Properly label the axes of an HR diagram and identify the
regions
Utilize the HR to identify a star’s luminosity, temperature,
radius and mass.
Interpret the luminosity class of a star by naming the
luminosity class (Table 59.1) and identifying if the star is in
the “adult” phase or the “nursing home” phase of its
evolution.
Unit 61: Star Formation
Describe the physical characteristics of a giant molecular
cloud
Identify the source of heating (energy production) in
protostars
Explain why more low-mass K & M main sequence stars
form rather than the high-mass O & B stars.
List the mass limits of stars and explain why these limits
apply.
Describe the processes and stages of star formation from a
giant molecular cloud to an open cluster.
Identify in a photograph the following objects: a GMC, Bok
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Luminosity
Class
V
IV
III
II
I
Name
“Adult” or “Nursing
Home” stage
Globule, OB Association, HII region, Open Cluster
Interpret the physical changes of a forming star on an HR
diagram.
Identify and define the ZAMS line on an HR diagram.
Describe the relationship between OB associations and HII
regions.
Unit 62: Main Sequence Stars
List or identify the luminosity, mass, radius, temperature,
and lifetime of an O main sequence star, the Sun and an M
main sequence star.
State the impact of convection in the envelope of very low
mass stars on the stars main sequence lifetime.
Describe or identify changes in a star during its main
sequence lifetime.
Unit 63: Giant Stars
Describe how shell fusion in a star causes the star to
become a giant.
Identify the “ashes” of H-burning and He-burning
Unit 65: Mass loss and Death of Low-Mass Stars
Match the stage of the Sun’s future evolution with the
mechanism of energy production in that stage.
Identify on an HR diagram the stage of the Sun’s evolution
and its mechanism of energy production.
List in chronological order the mechanisms of energy
production in Sun-like stars.
List in chronological order the stages of evolution in Sunlike stars.
Describe the relation between the Helium Flash and the
creation of a planetary nebula.
Describe the components and characteristics of a planetary
nebula.
Identify the characteristics of white dwarf stellar remnants.
Unit 67: Old age and Death of Massive Stars
List the differences in energy production between low-mass
stars and high-mass stars.
Describe the interior structure of a high-mass star near the
end of its lifetime.
Identify the types of stars that will experience a corecollapse (Type II) supernova.
Identify the composition of the core of a star about to
experience a core-collapse (Type II) supernova.
Describe two reasons why type II supernova a very useful
standard candles.
Describe the impact of supernovas on the chemical
evolution of the universe.
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Write out the acronym ZAMS and describe n words where it is on the HR Diagram.
Use the fluorescent light bulb analogy to describe the relationship between an OB
association and an HII region
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Complete the Take Home Quiz on Hot Tips under Week 9
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Summarize how convection can extend the lifetime of the lowest mass main sequence
stars (see section 62.2)
Summarize the three paragraphs of section 62.4 in three sentences.
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Problems
 Apply Wien’s Law to find the temperature of a star or its wavelength of maximum emission.
 Use the Stefan-Boltzmann Law to determine the luminosity, radius or temperature of a star compared to the Sun.
 Calculate the density of a star or other spherical object.
 Calculate the main sequence lifetime of a star.
 Use the angular size formula to determine the distance, or size of an astronomical object.
 Use t=d/v to solve problems related to the collapse or expansion of star-related objects
 Plus proportions and ratios