Download Notes 14-2

Notes 162
The Sun
Stars
an object
that
produces it
own energy,
including
heat and
light.
The Sun is a Star
• Star made of hydrogen and helium
• located at the center of the solar system
and is also the largest object
• Has a strong gravitational pull which
holds planets in orbit
• 4.6 billion years old
The size of the Sun
• If the Sun were a hollow ball more then a
million Earths could fit inside it!
• The Sun is an average size star and the
largest object in the solar system.
• The Sun looks larger than the other stars
that can be seen in the night sky because
it is much closer to Earth.
The sun is gas!
• The Sun is a huge sphere made up of
mostly of two gases.
– 71% of the Sun’s mass is Hydrogen
– 27% of the Sun’s mass is Helium
– The remaining 2% is Oxygen and Carbon
What happens inside the Sun?
• Hydrogen particles smash together to
make helium.
• This smashing is called Nuclear Fusion.
• A little bit of mass is a lost when
hydrogen particles combine to make
helium.
• The mass in turned into energy
• We see this energy as light and heat!
Interior Layers:
• The sun has 3 interior layers:
1) the core
2) the radiation zone
3) the convection zone
The Core
• Most of the energy that the Sun produces
is formed in it’s core.
• The Core’s temperature is 10 million to
20 million degrees Celsius.
• The pressure is more than 1 billion times
greater then the air pressure of Earth.
Radiation Zone
• Next to the core
• Moves the energy produced in the core in
every direction.
• It can take >100,000 years for energy to
move out of this layer.
Convection Zone
• Layer next to the radiation layer
• Gasses with different energies move in
circles in a way similar to air with different
densities.
• Energy moves out of this layer in about a
week.
The sun’s atmosphere:
• Has 3 layers:
1) photosphere
2) chromosphere
3) corona
Photosphere
• Is the visible surface of the Sun.
• It is not a solid surface, but rather a layer
of thick gasses.
• Gives off visible light
Chromosphere
• Is the inner layer of the Sun’s
atmosphere.
• When it can be seen it looks like a red
circle around the Sun.
The Corona
• The outermost layer of the Sun’s
atmosphere which creates solar winds.
• The corona takes on different shapes
around the Sun depending on changes in
the temperature of the photosphere.
Solar Flares
• Are bursts (eruptions) of heat and energy
that stretch out from the corona and
chromospheres into space.
• Sometimes the energy disrupts satellites,
interfering with TV, radio, and cell phone
communication systems.
Aurora Borealis
• Also called the Northern Lights
• Energy from the solar flares increases
solar winds, causing displays of differentcolored lights in the upper atmosphere.
• Most often seen in Alaska, Canada, and
the Northern United States
Sun Spots
• Solar Flares are also sometimes
associated with sunspots
• They are dark spots on the Sun.
• They are regions of the photosphere that
have a lower temperature then the
surrounding regions therefore they give
off less light.