Solar Flare

Sudden eruptions from the surface of the Sun. Flares typically last a few minutes and can release energies
equivalent to millions of hydrogen bombs. Flares become frequent near sunspot maximum, when smaller flares can occur daily and large flares can occur about once a week. During a flare the material in the flare may be heated to temperatures of 10 million K; matter at these temperatures emits copious amounts of UV and X-Ray, as well as visible light. In addition, flares tend to eject
matter, primarily in the form or protons and electrons, into space at velocities that can approach 1000 km/second. These latter events are coronal mass ejections, and produce bursts in the solar wind that influence much of the rest of the Solar System, including the Earth. The observation of a large flare on the surface of the Sun is usually a signal for increased auroras
and related activity several days hence when the ejected burst reaches Earth. Flares are also observed on other stars.