Earth, Sun and Moon

Solar Flares

Solar flares are sudden variations in the brightness of a surface region of the Sun. Magnetic energy builds up in the solar atmosphere, above active regions, where sunspots are located. This magnetic energy is suddenly released as radiation across the entire electromagnetic spectrum.


NASA image of sunspots
Sunspots at solar maximum

The visible surface of the Sun is called the photosphere. Sunspots are darker, cooler regions on the bright, hot photosphere. Whilst the photosphere has a temperature of around 6000°C, sunspots are between 3000°C and 4000°C.