Never look at the sun with your naked eyes umm ‘k?
Astronomers use special tools to study the sun.
Scientists can determine what gasses are present in stars by using a spectrograph.
They can also determine the stars temperature, density and pressure.
Because the sun is made of gas, no sharp boundaries
exist between its various layers. The sun is made of
99% hydrogen and helium.
• Nuclear fusion is the way that the sun produces energy. This
reaction converts four hydrogen nuclei into the nucleus of a
helium atom, releasing a tremendous amount of energy.
•During nuclear fusion, energy is released because some matter
is actually converted to energy (600 million tons of H to HE
every second).
• It is thought that a star the size of the sun can exist in its
present stable state for 10 billion years. As the sun is already
4.5 billion years old, it is “middle-aged.”
The Suns Interior
• The core is at the center of the sun, and makes up 25% of the
suns diameter
15,000,000 degrees C
Even though the core is all
Gas, its 10 times as dense
as iron
Homework
List the layers of the sun and the suns
atmosphere in the correct order. List the
temperature next to each layer.
• The radiative zone surrounds the core, and temperatures range
from 2,000,000 to 7,000,000 C
• Hot gases carry energy to the suns surface through the
convective zone. As the gases move up, they expand and
lose energy. Temps are 2,000,000 C
The Suns Atmosphere
• The photosphere is the innermost layer of the suns
atmosphere.
• Made from gases that have risen from the convective zone.
About 6,000 C
Most of the
energy given off
from the
photosphere is
visible light.
• The chromosphere (or color sphere) is above the
photosphere.
• The chromosphere is a thin layer of gases that glow a reddish
light typical from hydrogen. 4,000 to 50,000 C.
•The corona (crown) is the outermost layer of the solar
atmosphere. Can only be seen during a solar eclipse.
•Temperatures of over 1,000,000 C.
Homework
F. Earth’s rotation
H. Earth’s spherical
shape
G. Earth’s tilt on its
axis
I. Earth’s orbit about
the Sun
SWBAT
• Distinguish the various methods
of measuring astronomical
distances
• SC.912.E.5.11
https://www.youtube.com/watch?v=gIbfYsQfNWs
Learning Scale
Score 4.0
In addition to Score 3.0, in-depth inferences and applications that go beyond what was taught
•
Score 3.0
“SHOW”
Determine what method of problem solving would be appropriate in a new situation. Students will be able to
explain this lesson to others.
Learning Goal:
Students will be able to accurately measure the diameter of the sun using a meter stick and index cards.
Recognizes or recalls specific terminology:
o Diameter, sunspots, angle, altitude, kilometers, ratio, accuracy, precision
•
Targets
o Explain how the ancients used math to accurately estimate the suns diameter.
o Describe how continuous investigations and/or new scientific information increased
astronomical accuracy.
o Compare and contrast the size of the Earth and sun.
o Calculate the suns diameter.
The student exhibits no major errors or omissions regarding the score 3.0 content.
Score 2.0
“KNOW”
The student:
Recognizes or recalls specific terminology:
o Diameter, sunspots, angle, altitude, kilometers, ratio, accuracy, precision
•
Targets
o Identify sunspots.
o Define accuracy and precision.
o Describe a technique used to estimate astronomical sizes.
o Identify which object is larger, the sun or Earth.
No major errors or omissions regarding the score 2.0 content.
Score 1.0
With help, I know some of 2.0 and 3.0.
29.2 Solar Activity
The gases that make up the sun are in constant motion
with gases rising and sinking.
Because the sun is a ball of gas, not all points rotate the
same, but the sun rotates on average of once every 27
days.
Sunspots
Because convection causes some areas to become
cooler, dark sunspots occur.
• Sunspots appear dark because of their temperature, which is
about 1500 K less than that of the surrounding solar surface.
Sunspot Cycle
We have seen sunspots for hundreds of years, and
noticed sunspot numbers and positions vary in a cycle
that lasts for 11 years.
Solar Ejections
Prominences are great clouds of glowing gas that form
huge arches that reach high above the suns surface.
Some last hours, some last weeks.
Solar Flares are a sudden outward eruption of
electrically charged particles (e- and p+), and are the
most violent of all solar disturbances.
Can be as high at 20,000,000 C
Coronal Mass Ejections are parts of the corona that
are thrown off the sun. These can hit Earth and create
geomagnetic storms.
Geomagnetic storms can interfere with radio
communications on Earth, damage satellites, cause
blackouts when power lines are overloaded.
Auroras are bands of light created when solar winds
interacts with Earths magnetosphere. Usually seen near
the poles.
Homework
Study