The Sun is a medium-sized star, and is the closest star to the Solar System, being only ninety three million miles from our planet, the Earth. The Sun was created five billion years ago and is the Earth's main source of light, energy, and heat. The Sun is quite massive for a medium sized star, but is just the right distance from us to support life. The Sun is quite special, for the next closest star, Proxima Centauri, is more than four light years away from the Solar System.
The Sun was created five billion years ago by a giant nebula cloud. This cloud began to rotate in a circle due to accretion, creating tension and heat. This tension and heat turned the cloud into a sphere of flames and hot fire, thus creating the Sun. In fact, the Sun harnesses 99.86% of the Solar System's matter. This means that much of the nebula cloud was used in the creation of the Sun. The rest was used for the other planets and celestial bodies.
The Sun's atmosphere is called the corona. The corona can only be seen during an eclipse. The corona is one trillion times less dense than the photosphere, yet it can reach three million degrees Celsius. It extends millions of miles into space. Though the corona is the main atmosphere, before it is what is known as the transition region, the point at which the temperature transitions from the hotter parts of the photosphere, which is 36,000 degrees Fahrenheit, to the corona, reaching 1.8 million degrees Fahrenheit.
Solar flares are outburst of flames from solar wind, which can reach speeds one million kilometers per second. Solar flares release an abundance of radiation to the Earth, sometimes knocking out powerlines and causing power outages. Solar flares can reach extend one hundred thousand miles from the surface of the Sun. Solar wind is one cause of the extent due to the escape velocity of the Sun being 55 times the Earth's.
A prominence is an outburst of plasma from the photosphere, extending into the upper corona. No one is sure exactly how these prominences are formed, yet these can extend for thousands of miles across the surface of the Sun. Sometimes, these prominences can form in front of the Sun. They are then referred to solar filaments. These can last for weeks and can cause coronal mass ejections.
Sunspots are spots on the photosphere, or surface of the Sun. These occur due to magnetic activity that reduces the surface temperatures. These occur only once every eleven years. These spots can spread to be 50,000 miles in diameter. The inner cooler part of a sunspot is called umbra. The outer, paler part is called the penumbra.
Solar wind is the outburst of energized particles that can shoot off into space. These particles can reach speeds of over one million miles per hour. When these particles collide with atoms in the Earth's atmosphere, the aurorae light show is then formed.
Coronal Mass EjectionsEdit
A coronal mass ejection (CME) is an outburst of plasma from the Sun that is heading out into space. These mass ejections can reach speeds of seven millions miles per hour. These can be caused by prominences and solar flares. During a solar maximum, which is the time when an eleven-year process is at its peak of occurrences, up to five ejections can happen in one day. When these collide with Earth's atmosphere, they can cause aurorae that are very strong. They can even possibly interfere with radio communication devices.
A solar quake is a series of waves that travel across the photosphere of the Sun after a previous solar flare. These waves are clearly visible through space telescopes. They appear as ripple in a pond, yet they can reach to be four miles high. They can even extend to be eighty thousand miles long. They can even reach speeds of two hundred thousand miles per hour.
Miscellaneous Active RegionsEdit
When prominences are viewed in front of the Sun, they are called solar filament. This makes it appear darker than the surrounding area. Spicules are short-living jets of gas that appear on the surface of the Sun.
Granulation occurs when the Sun's photosphere appears to be sandy or mottled, hence the name "granulation". This occurs from convection currents of plasma in the convection zone of the Sun. The heads of these convective cells appear grainy and this causes the photosphere to appear to have granules.
The visible surface of the Sun. This layer can reach to be ten thousand degrees Celsius.
The convective zone is the layer beneath the photosphere. This layer is where the convection currents occur. Hot gas bubbles fall due to them being less dense than the surrounding air, so they rise. Then, after rising and becoming cooled, they become dense and then sink. This causes the photosphere to appear be boiling.
The next layer is the radiative zone, a zone where heat from the Sun's core is radiated to the convective zone. Radiation is the process at which heat is transmitted from one object to another.
The core is the last layer of the Sun, making up only two percent of the Sun's volume, yet making up 60% of its mass. This is also where photons, tiny packets of energy, are released, yet they take one hundred thousand years to travel to the photosphere.
Orbit around the Milky WayEdit
The Solar System rests on a cloud in the Milky Way galaxy known as the Oort Cloud. The Sun rotates around this cloud and then goes off course, traveling towards the center of the Milky Way galaxy. This process takes more than two hundred million years, and the distance is more than 26,000 light years.