The Sun
By: Chloe Boul
The Sun
The sun is what we call the giant star at the center of the Milky Way Galaxy. About 1 billion Earths could fit in the Sun. It's circumference is about 2,713,406 miles. But it's actually considered a medium-sized star. Compared to Betelgeuse, a red giant, it's tiny. Betelgeuse is about 700 times bigger and 14,000 times brighter. The sun gives energy through nuclear fusion, which uses molecules of hydrogen and helium. Hydrogen and helium are the two gases that make up the Sun (and also the first two elements on the periodic table). The Sun also has 6 distinct layers...
The Layers
The Sun has 6 distinct layers. They are (from inside out) the core, radiative zone, convective zone, photosphere, chromosphere, and corona.
Core
The core is the innermost layer of the sun, and the source of all the Sun's energy. It's temperature is 15,000,000 K.
Radiative Zone
The radiative zone is considered the "middle layer" of the sun's interior. It is where energy is transported outwards through radiation.
Convective Zone
The convective zone is the uppermost layer of the Sun's interior and has a temperature of about 14,000,000 K. This is where the energy is produced.
Photosphere
This is the visible "surface" of the Sun. The photosphere is where sunspots occur. Photosphere means "sphere of light".
Chromosphere
The chromosphere is transparent. It is visible immediately before or after a solar eclipse as a ring or crescent of of reddish color.
Corona
The corona is the outer atmosphere of the Sun. You can only see the corona directly during a solar eclipse. Corona means "crown".
Sunspots
Sunspots are darker areas on the Sun's surface. They happen when one area of the Sun is cooler than the other areas surrounding it.
Solar Prominence
A solar prominence is an arc of gas that erupts from the Sun's surface. They are held above the Sun's surface by strong magnetic fields and can sometimes last for many months and
Solar Flare
A solar flare is a magnetic storm on the Sun that appears to be a a very bright, gaseous surface eruption. They are ejected thousands of miles from the surface of the Sun.
Auroras
An aurora is a natural light display in the sky. It occurs when solar storms disturb the Earth's magnetic field, which causes it to rearrange itself and convert some stored energy into kinetic energy particles. These particles flow inward towards the Earth along the polar magnetic field lines. When they enter the ionosphere they collide with oxygen and nitrogen atoms to produce an aurora. This is more commonly known as the Northern Lights or the Aurora Borealis.
Cites
http://www.space.com/58-the-sun-formation-facts-and-characteristics.html
http://www2.mbusd.org/staff/bahrens/Sun_LayersP2.htm
https://www.eso.org/public/outreach/eduoff/vt-2004/mt-2003/mt-sun.html
http://solarcellcentral.com/sun_page.html
http://cronodon.com/SpaceTech/Sol.html
http://solarscience.msfc.nasa.gov/interior.shtml
http://www.iptv.org/exploremore/energy/energy_in_depth/sections/sun.cfm
http://kids.britannica.com/elementary/art-89898/A-cutaway-view-shows-the-extremely-hot-core-of-the
http://spaceplace.nasa.gov/violins/en/
http://www.computervisiononline.com/showcase/ring-fire
http://www.space.com/11506-space-weather-sunspots-solar-flares-coronal-mass-ejections.html
http://image.gsfc.nasa.gov/poetry/educator/Aurora79.html
http://www.enchantedlearning.com/subjects/astronomy/sun/prominences.shtml