Materials Required · Computer and internet access · Textbook · Scientific calculator · Spreadsheet software like Excel · Digital camera  · Printer or drawing software · Save this worksheet and use it as your report template Time Required: Between 3-3.5 hours, note that depending if you use Excel (or similar), your time will be shortened. Introduction Figure 1: JP Stellar Revolution The life cycle of the stars is one of the most fascinating studies of astronomy.Stars are the building blocks of galaxies and by looking at their age, composition and distribution we can learn a great deal about the dynamics and evolution of that galaxy. Stars manufacture the heavier elements including carbon, nitrogen and oxygen which in turn will determine the characteristics of the planetary systems that form around them. It is the mass of the star which will determine its life cycle and this all depends on the amount of matter that is available in its nebula. Each star will begin with a limited amount of hydrogen in their cores. This lifespan is proportional to (f M) / (L), where f is the fraction of the total mass of the star, M, available for nuclear burning in the core and L is the average luminosity of the star during its main sequence lifetime. The larger the mass, the shorter the lifespan ending in a beautiful supernova, the smaller the mass, the longer the lifespan ending as a quiet brown dwarf (Fig. 1). Main Sequence Stars Figure 2: https://imagine.gsfc.nasa.gov/ For this lab we will focus on stars similar to our own Sun (up to 1.4MassSun ), main sequence stars. A star that is similar in size to our Sun will take approximately 50 million years to mature from the beginning of their collapse to becoming an “adult” star. Our Sun, after reaching this mature phase, will stay on the main sequence of the HR-diagram for approximately 10 billion years (Fig. 2). Stars like our Sun are fueled by the nuclear fusion of hydrogen forming into helium at their cores. It is this outflow of energy that provides the outward pressure necessary to keep the star from collapsing under its own weight. And in turn, this energy determines the luminosity of the stars. Death of Our Sun Figure 3. NGC 6543 When a low mass star like our Sun has exhausted its supply of hydrogen in its core, then there will no longer be a source of heat to support the core against the pull of gravity. Hydrogen will continue to burn in a shell around the core and the star will evolve into the phase of a red giant, growing in diameter. The core of the star will collapse under the pull of gravity until it reaches a high enough density, and it will begin to burn helium and make carbon. This phase will last about 100 million years eventually exhausting the helium and then becoming a red supergiant, growing more in diameter. This is a more brief phase and last only a few tens of thousands of years and the star loses mass by expelling a strong wind. The star eventually loses the mass in its envelope, leav ...

1. Materials Required
· Computer and internet access
· Textbook
· Scientific calculator
· Spreadsheet software like Excel
· Digital camera
· Printer or drawing software
· Save this worksheet and use it as your report template
Time Required: Between 3-3.5 hours, note that depending if you
use Excel (or similar), your time will be shortened.
Introduction
Figure 1: JP Stellar Revolution
The life cycle of the stars is one of the most fascinating studies
of astronomy.Stars are the building blocks of galaxies and by
looking at their age, composition and distribution we can learn a
great deal about the dynamics and evolution of that galaxy.
Stars manufacture the heavier elements including carbon,
nitrogen and oxygen which in turn will determine the
characteristics of the planetary systems that form around them.
It is the mass of the star which will determine its life cycle and
this all depends on the amount of matter that is available in its
nebula. Each star will begin with a limited amount of hydrogen
in their cores. This lifespan is proportional to (f M) / (L), where
f is the fraction of the total mass of the star, M, available for
nuclear burning in the core and L is the average luminosity of
the star during its main sequence lifetime. The larger the mass,
the shorter the lifespan ending in a beautiful supernova, the
smaller the mass, the longer the lifespan ending as a quiet
brown dwarf (Fig. 1).
Main Sequence Stars
Figure 2: https://imagine.gsfc.nasa.gov/
For this lab we will focus on stars similar to our own Sun (up

2. to 1.4MassSun ), main sequence stars. A star that is similar in
size to our Sun will take approximately 50 million years to
mature from the beginning of their collapse to becoming an
“adult” star. Our Sun, after reaching this mature phase, will stay
on the main sequence of the HR-diagram for approximately 10
billion years (Fig. 2). Stars like our Sun are fueled by the
nuclear fusion of hydrogen forming into helium at their cores. It
is this outflow of energy that provides the outward pressure
necessary to keep the star from collapsing under its own weight.
And in turn, this energy determines the luminosity of the stars.
Death of Our Sun
Figure 3. NGC 6543
When a low mass star like our Sun has exhausted its supply of
hydrogen in its core, then there will no longer be a source of
heat to support the core against the pull of gravity. Hydrogen
will continue to burn in a shell around the core and the star will
evolve into the phase of a red giant, growing in diameter. The
core of the star will collapse under the pull of gravity until it
reaches a high enough density, and it will begin to burn helium
and make carbon. This phase will last about 100 million years
eventually exhausting the helium and then becoming a red
supergiant, growing more in diameter. This is a more brief
phase and last only a few tens of thousands of years and the star
loses mass by expelling a strong wind. The star eventually loses
the mass in its envelope, leaving behind a hot core of carbon
embedded in a nebula of expelled gas. Because the core is still
hot, its radiation will ionize the nebula, which is the planetary
nebula phase (Fig. 3). At the end the carbon core will cool and
become a white dwarf.
White dwarfs used to be quite a mystery. Astronomers couldn’t
figure out why the star didn’t continue to collapse. Quantum
mechanics brought about the answer - electron degeneracy
pressure. Read through this web material to learn more. In the

3. below table you will find important data that accompanies each
phase of a star like our Sun.
Table 1. Stellar Evolution of a Sun-like star. Reminder: When
we are examining the physical state of a star, we have to
separately consider the core (where temperature and pressure
are very high), and the surface (where the temperature and
pressure are considerably less). The core is where the fusion
occurs and the surface is what we can visually see. Thus, we
have to infer what is going on in the core by observing the
envelope of the star.
Table 1 Stellar Evolution of a Sun-like Star
Phase
Duration (years)
Diameter (meters)
Density (kg/m3)
Core Temperature
(Kelvin)
Surface
Temperature
(Kelvin)
1. Interstellar Cloud
2.13x106
6x1017
1.67x10-18
10
10
2. Protostar
(phase 1)
106
1011
.001674
1x106
3,000
3. Protostar
(phase 2)
1x107

4. 1x1010
16.74
5x106
4,000
4. Main Sequence Star
1x1010
1.4x109
1x105
1.5x107
5,770
5. Red Giant
1x108
4.2x109
1x107
5x107
4,000
6. Red Giant (before helium flash)
1x105
1.4x1011
1x108
1x108
4,000
7. Red Giant (after helium flash)
5x107
1.4x1010
1x107
1x108
5,000
8. Super Giant
1x104
7x1011
1x108
2.5 x 108
4,000
9. Carbon Core
1x105

5. 1.4x107
1x1010
3x108
1x105
10. White Dwarf
1x10?
1.4x107
1x1010
Starts at 3x108 and cools down
Starts at 1x105
and cools down
1. Activity
Note: Even if you use Excel for your work below, you will still
want to show one calculation of each type fully worked out in
detail. (typed) Again, it would be helpful to review the
Exploration from Module 1: “Math Primer for Astronomy” (note
this contains link for a free online scientific calculator). There
are also good math examples in the Appendix of our eText.
The evolution of any star is a complex process. In order for us
to understand the processes that are taking place and how stars
change with time scientists must apply the basic ideas of
physics and chemistry to create a mathematical model of a star.
By making many observations of many types of stars along with
stars at various stages in their lifespan, we can use these
observational clues to test these models. By plugging in many
variables into sophisticated computer programs we are able to
come up with a theory of stellar evolution and this, in turn, can
give us the story behind every sort of object in the sky from a
main sequence star, supernovae, black hole, to nebulae. Using
the information from Part 1 of this lab, let’s see what we can
find out about some of the phases that our Sun has and will go
through.
A Balancing Act
In looking at Table 1, during the protostar stage our Sun is
contracting under its own weight and this results in a rising
temperature. Looking back to the ideal gas law, in Chapter 14,

6. we find:
Pressure x Volume = (Number of particles) x (k) x (Temperature
of the gas)
or
where k = 1.38 x 10-23 [joule/K] is Boltzmann’s constant. This
law applies to all gases consisting of simple, freely flying
particles, like in our Sun. We can also relate this formula to the
forces being applied.
In a star, the pressure will always be changing with the radius,
and this keeps the star from collapsing. At each layer, the
outward push of the gas is balanced by the inward pull of
gravity on the gas. In looking at the above relationship between
the variables, if one changes then the others must change to
balance the equation out. Thus:
A. As our Sun is in the phase of Interstellar Cloud, describe
what force is acting while the cloud is collapsing.
B. Describe also what is taking place in terms of conservation
of energy, what is happening to the kinetic and potential and
thermal energy as the cloud is collapsing?
C. For each of the Protostar phases calculate the luminosity
using: L=(σT4 ) ×(4πr2 ) which is power (energy per second
per unit area) times the surface area. (L: luminosity in
Watts σ=5.67×10−8[(W/m2)/K4= 3.14; r: radius in meters)
a. Calculate luminosity of Protostar phase 1:
b. Calculate luminosity of Protostar phase 2:
c. What was the difference in luminosity between the two
phases?
d. What was the surface area 4πr2 for each Protostar phase?
How much did it change?
e. What variable, surface temperature or radius affected the
luminosity the most during the change from Protostar phase 1 to
2? Why? (Hint: think of percent increase or decrease.) Online
calculator
Main Sequence Phase

7. Once our Sun was about 13 million years old and had reached a
temperature of approximately 107 Kelvin, a special process was
about to take place. The luminosity also settles down to
around 4×1026 Watts. It is during this time that the process of
fusing hydrogen takes place, two atoms of hydrogen coming
together to produce helium.
A. How many reaction cycles per second was our Sun fusing
hydrogen in order to release enough energy to radiate 4×1026
Watts? (Hints: Each fusion reaction cycle yields 4.3×10−12
Joules, and Watt is a unit of power = [Joules/second], and you
are wanting to find a number of units [1/seconds].)
B. If each reaction cycle yields 4.3×10−12 Joules, how much
mass per second is the Sun converting into energy? (hint: use
Einstein’s equation E=mc2 and solve for mass, E = energy for
each reaction cycle, M = mass in kilograms, c = speed of
light 3×108 note that units of Joules = [kg·m2s2] Then you can
multiply that number by what you found in A., which was (#
reactions/second) ending up with (mass/second).
C. Explain why the Sun is at equilibrium during this phase of
main sequence.
D. Create a table similar to the one at the end of this lab, titled
“Luminosity Table” to put in your lab report. Fill in the
luminosity stated above for the main sequence line.
Red Giant Phase
In the main sequence phase, the Sun’s diameter is 1.39×109
This tells us it has a mean density of approximately 1400 kg/m3
We can compare that to the density of water, which
is 1000 kg/m3 What is the mean density of the Sun as it is in its
Red Giant phase? Hint: (density=massvolume
and volume=43πr3 and assume that the mass remains roughly
the same.)
A. If the Sun’s diameter continues to increase, what will happen
to the density? Explain your answer.
B. Calculate the luminosity of the Sun at this phase. (Use
equation from above and put this number into your Luminosity
table for the Red Giant phase.) Hint: You can create a

8. spreadsheet with the luminosity formula and data from Table. 1,
this would allow you to calculate the luminosities quite quickly.
Make sure to show at least one sample calculation done by
hand. How to Create Formulas and Make Calculations.
Red Giant - before helium flash phase
Figure4. Institute for Astronomy
Up to the time before the helium flash the core temperature
continues to rise and
reaches 108{"version":"1.1","math":"<math
xmlns="http://www.w3.org/1998/Math/MathML"><msup ><mn>
10</mn><mn>8</mn></msup></math>"} Kelvin, and a core
density of 108kg/m3{"version":"1.1","math":"<math
xmlns="http://www.w3.org/1998/Math/MathML"><msup><mn>
10</mn><mn>8</mn></msup><mi>k</mi><mi>g</mi><mo>/</
mo><msup><mi>m</mi><mn>3</mn></msup><mspace
linebreak="newline"></mspace></math>"}. At this point the
helium fuses to ignite a “triple-alpha process”: two helium
nuclei collide and fuse to make beryllium, releasing energy, but
before the beryllium can break down another helium collides
with it to form carbon, releasing more energy. This helium flash
releases more energy than had been radiated over 30,000 years
while the Sun was in its main sequence phase, all in just a few
seconds.
A. If the helium flash released 30,000 years worth of energy (as
in the main sequence phase) in just 10 seconds, what would be
the amount of power that was radiated? Hint: (Remember your
units! How many seconds are in a year? If the luminosity
was 4×1026{"version":"1.1","math":"<math xmlns=" Unknown
node type:
a "><mn>4</mn><mo>&#xD7;</mo><msup><mn>10</mn><m
n>26</mn></msup></math>"}Watts? Power=Watttime, power
has units of [Joules])
B. Compare that power to what a single hurricane might
generate, 1.3×1017{"version":"1.1","math":"<math
xmlns="http://www.w3.org/1998/Math/MathML"><mn>1</mn>

9. <mo>.</mo><mn>3</mn><mo>&#xD7;</mo><msup><mn>10<
/mn><mn>17</mn></msup></math>"}Joules in one day, which
is equivalent to about half the world wide electrical generating
capacity. Does that even come close to the number you
calculated?
C. Calculate the luminosity of the Sun at this phase. (Use
equation from above and put this number into your Luminosity
table.)
Red Giant - helium fusion after helium flash phase
Over the next 105{"version":"1.1","math":"<math
xmlns="http://www.w3.org/1998/Math/MathML"><msup><mn>
10</mn><mn>5</mn></msup></math>"} years the core settles
into stable helium fusion surrounded by a shell of hydrogen
fusion. During the helium flash, this explosive event would
produce strong convection currents in the outer envelope of the
Sun and perhaps blow out 20-30% of it out into space. In turn,
the outer envelope of gas gets hotter. The core will consume the
helium quickly because of the high temperature, the triple-alpha
fusion lasting maybe on a few million years.
A. Calculate the luminosity of the Sun at this phase. (Use
equation from above and put this number into your Luminosity
table.)
Red Giant becomes Super Giant
By this time helium is running out of the core, which is mostly
carbon now surrounded by a shell of fusing helium and an outer
shell of fusing hydrogen. The core is small and massive and
heating up. Eventually, the fusion days are coming to an end.
The hydrogen shell dumps helium ash onto the helium fusion
shell, then the helium shell dumps its carbon ash into the carbon
core. The core continues to contract, which shrink the outer
shells. Again temperatures rise and as a result the star bloats up
again but even bigger into a super giant.
A. For the Super Giant phase calculate the average density.
(Hint: use the above equation for density, assume the mass is
still 2×1030{"version":"1.1","math":"<math
xmlns="http://www.w3.org/1998/Math/MathML"><mn>2</mn>

10. <mo>&#xD7;</mo><msup><mn>10</mn><mn>30</mn></msu
p></math>"} kg.)
B. Calculate the luminosity of the Sun at this phase. (Use
equation from above and put this number into your Luminosity
table.)
After the Super Giant phase
Finally all of the available gravitational energy is spent. The
fusion stops, leaving a carbon core. But just before the core
goes out, the outer envelope is transformed. During this period,
a number of helium flashes can occur, destabilizing the gas and
causing pulsations. The gas would rise and fall a few times until
finally it rises fast enough to escape from the core - and we will
see a beautiful planetary nebula.
The Carbon Core
By this time our Sun is not shining by fusion, and no longer
technically a star, but it is back in equilibrium.
White Dwarf
At this point our Sun starts to cool off and radiate light.
A. For the surface temperature
of 105{"version":"1.1","math":"<math
xmlns="http://www.w3.org/1998/Math/MathML"><msup><mn>
10</mn><mn>5</mn></msup></math>"}Kelvin, what is the
initial luminosity of the white dwarf?
B. How do you think the luminosity will change over time?
C. Convert your luminosities in the below table to solar units
(by dividing each by 4×1026{"version":"1.1","math":"<math
xmlns=" Unknown node type:
a "><mn>4</mn><mo>&#xD7;</mo><msup><mn>10</mn><m
n>26</mn></msup></math>"}Watts). Hint: this will be very
easy if you have created an Excel spreadsheet with the
luminosity formula. Please upload your Excel file to the
assignment folder with your lab report.
D. Print out the below HR Diagram plot and label each of your
luminosities in pencil from the Luminosity Table you create.
(Note: if you have drawing software, you can use the image and
draw the below.)

11. a. Draw an arrow in the direction the path will follow from one
phase to the next.
b. Draw a path from the Super Giant phase to where you think
the Sun will end up. (Remember, over time how this path would
look on the HR Diagram.)
Luminosity Table (to create and place in your lab report)
Phase
Luminosity (in Watts)
Luminosity in Solar units
( L/4×1026Watts)
4. Main Sequence Star
5. Red Giant
6. Red Giant (before helium flash)
7. Red Giant (after helium flash)
8. Super Giant
HR Diagram (print out, and follow instructions to fill it in, and
place in your lab report)
Foundations of Emergency Management: Point Paper
1. Topic: National Disaster Medical System (NDMS)
Instructions: The content of your paper must be at least 7 pages
in length (double-spaced, Times New Roman 12
font), not including cover page, references, appendix, tables,
etc. The format of the paper must include:

12. 1) submit in Word document and not PDF;
2) a Cover page, which must include the title of the paper, your
name, date of submission, and course name;
3) an Abstract or Introduction, which states the purpose of the
paper;
4) Sub-headers for each topic as prescribed by
the Guidelines listed below, which also serves as the evidence
to be graded; and
5) a Conclusion, which summarizes your research findings, and
includes comments of your personal perspective about the
topic. The research paper must include a minimum of five
(5) references, which must be properly cited using APA
(7th edition) guidelines. Never use Wikipedia, which is
unacceptable. All papers are filtered by Canvas through Turnitin
(https://www.turnitin.com/). Evidence of plagiarism will result
in a failing grade. You may also lose 10 points every day the
paper is late. Follow the instructions carefully to earn a good
grade.
Point Paper #2 Guidelines & Grading Scale > 100/100
First, conduct thorough research for the ‘Topic’, and be sure to
use/cite a minimum of five (5) reference sources > APA
7th edition, citation/bibliography format. (10/10)
Second, outline the history, goals and objectives of the
program: sub-header > History, Goals, and Objectives of the
Program. (25/25)
Third, detail annual funding for the program source(s), amount,
etc.: sub-header > Program Funding. (25/25)
Fourth, discuss the programs relation to Emergency
Management at the State/Local level: sub-header > Program
Relative to Emergency Management at State/Local

13. Level. (25/25)
Fifth, must include the following: Cover page, Abstract,
Conclusion, Sub-headers,
Bibliography, spelling/grammar/punctuation; references
cited; APA 7th edition format. (15/15)
Again, the deadline for submission of this paper is Midnight
(central time), Sunday July 17, 2022. You will lose 10
points every day the paper is late.