THE SUN AND STARS
And anything I want to put in here.
STRUCTURE OF THE SUN
The sun is 93 million miles from earth, how do we
know so much about it?
Scientist look at the sun’s light with a device called a
spectrograph. Dark lines form in the spectra of stars
when gases in the stars’ outer layers absorb specific
wavelengths of the light that passes through the layers
Each element present in the sun will produce a
unique pattern of spectral lines. Scientist can use the
lines to identify the elements in the stars atmosphere
The sun’s mass is about 99% hydrogen and
helium, as a matter of fact, all stars contain
hydrogen and helium
THE SUN’S INTERIOR
The sun’s interior can not be seen by scientist, but
computer models have revealed possibly what it
would be like. Using information from the surface,
scientist can deduce what must be happening inside
to produce such effects.
Three parts to the sun’s interior: core, radiative
zone and convective zone.
CORE
Diameter: 1,390,000 km
Temperature: 15,000,0000C
Mass: 300,000 times greater than earth
Core is so dense with ionized gases you could stand on
it
Because of the high temperature and pressure, nuclear
reaction occur, nuclear fusion.
RADIATIVE ZONE
Energy from the core is radiated to this zone.
Temperature ranges form 2,000,000 0C to
7,000,0000C
Energy moves outward in the form of
eletromagnetic waves called radiation.
CONVECTIVE ZONE
Energy that is produced in the core moves through
this zone by convection
Carries hot gases to the surface of the earth
Temperature: 2,000,0000C
Gases rise and sink because they cool as they move to
the sun’s surface.
THE SUN’S ATMOSPHERE
Although the sun is made of gases, the
term atmosphere refers to the uppermost
region of the solar gases. This region has 3
layers: photosphere, chromosphere, and the
corona.
PHOTOSPHERE
The innermost layer of the solar atmosphere
is the photosphere
Temperature: 6,0000C
Part visible from earth, gives off visible light
Has sunspots
CHROMOSPHERE
Chromosphere lies above the photosphere.
Temperature: 4,000 to 5,0000C
Glows reddish, gases move away from the
photosphere
Gases of the chromosphere will shot out
CORONA
The corona is the outermost layer of the sun’s
atmosphere.
Temperature: 1,000,0000C
Only visible during an eclipse
Escaping particles, ion, blow away forming the solar
wind.
ASSIGNMENT
Go to Page 758
Sketch and label the drawing.
HOW THE SUN GET
ENERGY
A powerful atomic process know as nuclear
fusion occurs inside the sun. Because of the
high temperature and pressure, nuclei are
opened and particles are changed and energy is
released
Step1: Two hydrogen nuclei or protons,
collide and fuse. ( the positive charge of one of
the protons is neutralized as that proton emits a
particle called a positron. As a result, the proton
becomes a neutron and changes the original two
protons into a proton neutron pair.
Step2: Another proton combines with this
proton neutron pair to produce a nucleus
made up of 2 proton and one neutron.
Step 3. two nuclei made up of two
protons and one neutron collide and fuse
As this fusion happens, two protons are released.
The remaining two protons and two neutrons are
fused together and form a helium nucleus and
energy is releases
Go to Page757 for mini lab explaining the process
http://youtu.be/pusKlK1L5To
MASS CHANGING INTO
ENERGY
Only 70% of the mass of the hydrogen is
converted to helium during nuclear fusion.
What happens to the 30% left? It is changed
into energy. Remember…Matter is neither
created or destroyed.
 In 1905, Albert Einstein proposed an
explanation for the production of energy.
The theory become knows as Relativity.
E = mc2 Where E is energy, m is mass
and c2 is the speed of light.
CALCULATIONS
Mass of 6 hydrogens = 6.042

4.03176
Mass of helium= 4.002602
4.03176-4.002602=.029158
CALCULATIONS
E =2.040 x186,0002= bazillion X 107
This is the energy made. Millions of atoms
are converted per second producing tons of
energy. The number above is for only one
Helium being produced. #WOW!
SOLAR ACTIVITY
The sun is a ball of hot gases rather than a solid
sphere, not all locations on the sun rotate at the same
speed. Places close to the equator on the surface of the
sun take 25.3 earth days to rotate once. On average, the
sun rotates once every 27 days.
SUNSPOTS
The movement of gases within the
convective zone and the movements
caused by the sun’s rotation produce
magnetic fields. There magnetic fields
Cause convection to slow in parts of
the convective zone. Slower convection
produces cool areas. The cooler areas
of the sun appear darker and are called
sunspots.
Sunspot activity appears to follow an
11 year cycle , slowing increasing then
decreasing their
numbers.
SOLAR EJECTIONS
Because of the continuing changes in
the magnetic field, there are 3 types of
solar ejections produced: prominences,
solar flares and coronal mass ejections.
PROMINENCES
Great clouds of glowing gases, called
prominences, form huge arches that reach
high above the sun’s surface. Each arch
follows curved lines of magnetic force from a
region of opposite polarity to another.
SOLAR FLARES
The most violent of all solar
disturbances is a solar flare, a sudden
outward eruption of electrically charged
particles, such as electrons and protons
Solar flares release the energy stored
in the strong magnetic fields of
sunspots. During peak of sunspot
activity, there may be 5-10 sunspots a
day
CORONAL MASS EJECTIONS
Coronal mass ejections are parts
of the corona thrown off by the
sun. CME’s are full of electrons
Which interact with the earth’s
magnetosphere. This produces
geomagnetic storms, which can
interfere with radio communication
and power lines
AURORAS
A spectacular effect occurs between
the solar wind and Earth’s
magnetosphere – Aurora. The
electrically charged particles from the
Solar winds interact with earths
magnetic field. The electrons strike the
gases in the atmosphere and produce
beautiful dancing light