Solarflares from our active Sun

This year our Sun is very active. It is in it's most active part of it's cyclus and that means regular solarflares that are a lot stronger then ususal.
Once every eleven years the magnetic poles of the Sun change place, causing a low magnetic field. This allows more and stronger explosions on the surface of the Sun, called solarflares. If a solarflare is strong enough it can cause probems on Earth with electricity and radio since the flares send electro magnetic radiation into space.

Solarflares are classified into three categories. The C category is the weakest and will cause no problems on Earth where the M category can cause radio problems around the poles. The X category is the strongest and if the outburst is pointed in the direction of the Earth it can cause problems.
The Sun always has small solarflares that never reache the surface of the Earth but can cause the beautiful aurora above the poles. This year however it will reach it peak in activity and already in May it produced three solarflares of the X category. Also in July a strong solarflare was registered by the NASA.
So far the solarflares have caused no problems and come nowhere near the strength of the worst solarflare ever recorded in September 1859. That one was visible with the naked eye and caused chaos, in these times where we have become so dependend on electricity and devices the effect would be even greater.
Let's hope this cyclus will pass again with a minimum of disruption.

Our closest star, the Sun

The Sun is our very own star. It gives us light, energy and warmth and without it, life could not exist on Earth. But what is a star and what kind of star is our Sun?

A star is a huge sphere of very hot, ionised gas. Because of the pressure and temperature in the core of a star, a nuclear reaction takes place that forms helium from hydrogen. This generates enormous amounts of energy, which is slowly carried outward until it finally reaches the surface and radiates out into space in the form of heat, light and other forms of radiation. This journey of energy to the surface can take up to a million years. Our Sun is a quite small and average star in the main sequence. Its surface has temperatures of about 5.500 degrees Celsius, which results in a yellowish light. Hotter stars will appear