Raw power of the Sun

 Flare on 12 May Solar filament and flare on 3 May 2013  Between 12 and 14 May, the Sun unleashed four intense bursts of radiation, or flares. These X-class flares - the most intense type - represent the strongest activity on the Sun so far in 2013. This picture from Nasa's Solar Dynamics Observatory (SDO) shows the first of these on 12 May.

  

 Flares are associated with eruptions known as coronal mass ejections, or CMEs. These can release billions of solar particles into space in the form of charged gas and other material. This picture from the Stereo spacecraft shows a CME earlier this year. The black disc blocks out the Sun so that fainter features can be seen.

 Flares and CMEs originate around active regions known as sunspots. These are temporary dark patches on the Sun caused by magnetic activity. The recent flares were released from a sunspot called AR1748; this picture, taken in 2010 by the New Solar Telescope in New Jersey shows a different feature.