The sun has 5 main parts:
Core-
The core is the middle of the sun located from the center to
about .2 radii. It’s density can reach up to 150,000 kg/m. That
is 150 times the density of water! The temperature averages arouns
13,600,000 Kelvin. The core is different from the rest of th eparts
on the sun in that it is the only place that heat is develeped by fusion,
where the rest of the sun is heated by energy transferred outward from
the core. After traveling through many layers and finally reaching
the Photosphere, the energy is released into space as sunlight and
kinetic energy.
Radiation Zone-
The Radiation Zone is located from about .2 to .7 radii, the layer that
sits right next to the core. The Solar material present is hot and dense
enough so that thermal energy can be transferred outward from the core.
Heat is transferred from radiation. Ions of materials like hydrogen and
helium release photons. They travel until they are absorbed by other
ions. It is kind of ironic that is takes millions of years for light
to escape from this layer of the sun, but after this, it takes 8 minutes
to reach the earth.
Convection Zone-
the Convection Zone is located form .7 radii to the outermost visible
layer of the sun. Thermal columns carry hot materials to the photosphere
(the surface of the sun) because the material in the sun is not dense
enough to transfer heat energy from the interior to the photosphere by
radiation.
Atmosphere
The atmosphere of the sun is made up of three sections; the photosphere,
the chromosphere, and the solar corona.
Photosphere-
the Photosphere is the uttermost visible layer of the sun. The
photosphere is tens to hundreds of kilometers thick. It opacity, which
is slightly than that of air on Earth, is caused by the decreasing
amount of H-ions. The upper part of the photosphere is cooler than
the lower part. This makes an image of the sun brighter in the center
than on the edge or limb, or solar disk. This is known as limb darkening.
Chromosphere-
The chromosphere is located above the photosphere. It is about 2,500
km thick. It appears as a reddish ring, before and after the peak of
a solar eclipse. Chromosphere means “colored sphere”.
The Solar Corona-
The Corona begins at the top of the atmosphere.
The Corona is very rarely visible because it only shows during a solar
eclipse. This is because the glow of the photosphere is 1 million times
as bright as the corona, making it only possible to see when the photosphere
is blocked. One other way scientists view the Corona is by using a
coronagraph, or coronameter. The Corona is so hot that it emits light
at X-ray wavelengths. The Corona’s temperature is 1 million degrees,
but it is 10 billion less time less dense than the atmosphere on earth
at sea level.
SSunspots and the Solar Cycle
Sunspots are the most visible features on the outer layer of the sun. Sunspots occur in regions with strong magnetic activity. In these regions convection will occur. Convection is the internal movement of currents within fluids. This results in a lack of energy being transferred from the hot interior of the sun to the outer layers of the sun.
The number of visible sunspots varies over the period of the Solar Cycle. The Solar Cycle takes form 10 to 12 years. Sometimes none can be seen at all. As the sunspot cycle progresses, more and more sunspots can be seen. Usually Sunspots come in pairs. The pairs have opposite magnetic polarity. This is where the magnetic North Pole is actually in the South Pole. This will eventually happen to earth. The polarity of the sunspot pairs alternate every solar cycle. Thus, if one solar cycle’s the polarity of the leading sunspot is in the north, next solar cycle it will be in the south. Magnetic Fields switch with the polarity of the leading sunspot.
Extra Information
It is Earth’s main light source. During the day, this is what makes
one side of the world bright. When earth rotates, it turns to face away
from the sun, making the moon our source of light at night however it
is not nearly as bright.
• The sun makes up approximately 98% of our solar systems mass.