Sunny Days
The sun is the closest star to us here on Earth.The sun, like all other stars, is fueled by nuclear fusion reactions. It has three parts of its visible atmosphere: the photosphere, chromosphere and solar corona. Many people believe that there are only three states of matter- solid, liquid and gas. However there a fourth, less commonly known state -plasma. Plasma is a gas that behaves like a liquid. The sun is made primarily of plasma. The sun may appear to have dark regions on its "surface". Theses areas are called sunspots. Sunspots are cooler regions on teh sun; they are about 4000 degrees Kelvin. These sunspots may appear to be very small in size, but in fact, they are the very size of Earth. Sunspots are caused by magnetic fields and cause solar flares and coronal mass ejections.
What is a
Star?
A star is basically a massive ball of hot dense gas that crates and emits its own radiation. They are formed within clouds of dust in space. When a cloud collapses, the center gets hot. That is the material of future stars. The color of the star relates to its temperature. Blue, for example is the hottest while dark red has the coolest temperature.
Nuclear Fusion: Hydrogen atoms fuse together to make Helium. At high temperatures, the ions and electrons separate. If these particles can overcome the electrostatic forces, the nuclei will join. This occurs in the sun because it is very hot causing ions to move faster and closer together, soon getting close enough to fuse. This fuse causes a release of energy.