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Define Fusion
Fusion is the combining of lighter atomic nuclei to make
heavier atomic nuclei and energy. In the Sun, hydrogen is
fused together to make helium.
Define Fission
Fission is the opposite of fusion. It is the splitting of heavy
atomic nuclei into smaller atomic nuclei and energy.
How many Jupiter's would it take side by side to go
across the Sun?
10
How many Jupiter's would it take to fill the Sun?
100
What percent of the solar system does the Sun’s
mass make up?
99%
What are the three layers of the Sun’s atmosphere?
1. Photosphere
2. Chromosphere
3. Corona
Which layer of the Sun’s atmosphere can you see?
Photosphere
Which layer of the Sun’s atmosphere is the outer
most layer?
Corona
Which layer of the Sun’s atmosphere is the thickest
and the hottest?
Corona
Which layer of the Sun’s atmosphere is in the
middle?
Chromosphere
What are the violent eruptions of particles of
radiation?
Solar flares
What is the arc of gas that is ejected from
the photosphere and rains back to the surface?
Prominence
Where does the fusion process take place?
In the Sun’s (stars) core
What formula describes the energy-mass conversions
for a stars fusion?
E = M C^2
What is the density found at the Sun’s core and how
does it compare to lead?
150 g/cm^3 or 1.5 X 10^5
13 times more dense than lead
How much longer will the Sun last?
About 5 billion years
What is the hydrogen turned into during the fusion
process?
Helium
How is it possible for the Sun’s core to be 13 times
more dense than lead, but still be in a gaseous state?
The temperatures are so high! (27 million degrees F)
List and describe the three different types of spectra?
1. Continuous
a) No breaks between the wavelengths
b) As seen through a prism, no gas
2. Emission
a) See particular wavelength bands
b) As seen from a non compressed gas
3. Absorption
a) See dark bands along spectrum
b) As seen coming through a cool gas
What is the Sunspot cycle?
About 11 (11.2) years
What is the Sunspot cycle if you take into
account the flipping of the Sun’s magnetic field?
About 22 (22.4) years
What is the percent hydrogen and Helium in the Sun?
Hydrogen = 73.4%
Helium = 25%
What is a group of stars that form a “picture”?
Constellatiion
Why can’t you see some constellations like Orion all
year long?
As the Earth orbits the Sun, you can’t see the
constellations on the other side of the Sun because
the Sun is too bright to see stars during the day.
What are the Zodiac constellations?
These are the 12 constellations that mark where the
Sun, Moon and planets appear to pass through,
throughout the Year.
Are all of the stars within a constellation next to each
other?
No, the stars can vary greatly in distance to Earth, but
we can’t visually distinguish the difference in depth
so they only appear to be next to each other.
What do you call it when 2 stars are gravitationally
bound to each other?
Binaries
How common are Binaries?
Over half of the stars you see are actually binaries.
What is a Doppler shift?
As energy moves towards an observer the waves
compress (gets shorter) and shifts to the color blue.
As energy moves away from an observer, the waves
elongate and shift to the longer color red.
What color shift do we see when we look at most
galaxies and why?
We see a red shift, because the Universe is
expanding.
Why can’t we tell with the naked eye if a star is a
binary?
They are two far away (for our eyes to resolve the
one image as two points of light).
What is the name of the process of determining the
distance to a star based on the shift of its image
throughout the course of the year?
Parallax
Describe how the parallax process works?
As the Earth orbits the Sun, our view of a give star
shifts. The more it appears to shift, the closer the
star is.
What is the measure of a stars brightness?
Magnitude
What are the two types of magnitude?
Absolute and Apparent Magnitude
What is apparent magnitude?
How bright a star appears to be.
What is parsec?
3.26 ly
What is absolute magnitude?
How bright it actually is based on size and temperature
at a distance of 10 pc (32.6 light years).
What is the measure of a stars brightness?
Magnitude
Define Luminosity
The measure of a stars energy output per second.
Why do the planets orbit the Sun?
The Sun’s gravitational pull keeps the planets from
flying out of the solar system.
The magnetic storms that are cooler areas on the
Sun’s surface are known as what?
Sun spots
How is Einstein’s theory of Relativity expressed and
what do the letters mean?
E = M C^2
E = energy
M = Mass
C = the speed of light and its squared
What is a circumpolar constellation?
A constellation that is close to Polaris and can be
seen all year round.
What is the difference between apparent and
absolute magnitude?
Apparent magnitude is how bright a star appears,
and absolute magnitude is how bright the star
actually is.
What are the two main ingredients for a star?
Hydrogen and helium
What are the spectral classes for the stars?
O, B, A, F, G, K and M and each class can range from 0
to 9.
How does the spectral class relate to the stars
temperature?
The O stars have the highest temperature (50,000 K) and
gets progressively cooler down to the M stars (2,000 K).
What is the spectral class and surface temperature in
Kelvin for the Sun?
G2
5,800 K
Give all of the information possible about the Sun
from the HR diagram
(not in ESRTs ) Spectral Class = G2
Temperature = 5,800
Color = yellow
Type = Main Sequence
Luminosity = 1
Which is the hottest spectral class?
O
What two things determine the Temperature and
Hydrostatic equilibrium?
The mass and composition of the star
Name 2 things that the temperature of a star will
determine
The luminosity and rate of nuclear reactions.
Most stars in the galaxy are in what group?
Main sequence
Define Hydrostatic equilibrium
The balance between the outward explosive force of
a nuclear reaction, and the pull inward due to
gravity. This makes the spherical shape of a star.
What does every star start out as?
A nebulae (collection of hydrogen gas)
Describe the first stages of life that all stars go
through to become a star.
The nebulae collapses upon itself and rotates. As it
continues to contract it gains pressure and
temperature until fusion begins
What does the rest of the stars cycle (after the birth)
depend on?
Its mass
How long does an average size star like the Sun last?
10 billion years
What is the final stage of a large (not the largest)
star?
A supernovae  Neutron star
What happens to the largest stars at the end of their
lives?
They implode and become black holes
What is a black hole?
A massive body in space that is so dense, that not
even light can escape its gravitational pull.
List and describe the two main types of black holes?
Stellar: made from a single giant star imploding
Supermassive: found at the center of most galaxies.
What is at the center of our Galaxy?
A super massive black hole
What do average and smaller size stars turn into at
the end of their life cycle?
Black Dwarfs
What is the next stage for a star like our Sun, and
what will happen as a result?
It will become a Red Giant (expanding greatly in size)
and bake the inner planets.
What is the explosion of a neutron star called?
Supernovae
What is the center of the Sun called?
Core
What color do we see because the stars and galaxies
are moving away from us?
Red
How far away is the Sun from Earth?
93 million miles or 8 light minutes
What is the unit of distance from the Earth to the Sun
called?
Astronomical Unit or AU
What is the unit of distance equal to 3.26 light years?
Parsec
Which group of stars has the lowest luminosity?
Dwarfs
Which color would a star be to signify the highest
temperature?
Blue
Which color would a star be to signify the lowest
temperature?
Red
Which color is the Sun?
Yellow
How could a medium size star like the Sun appear to
be brighter than a super giant?
Because it is so close
What is the relationship between the magnitude
number and brightness?
The lower the number the brighter it is.
Which star has a higher temperature, Spica or
Barnard’s Star?
Spica
Which star is Larger, Sirius or Deneb?
Deneb
What group do most stars belong to?
The Main Sequence
What is the temperature of Spica?
25,000 K
In what ways are Polaris and the Sun similar and in
what ways are they different?
Similar: Color and temperature
Different: Size and luminosity
What group does Deneb belong to?
Supergiants
How many days does it take the Sun to rotate?
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