Circular Solar Outburst

A round solar prominence burst from the sun on March 13, 2016, shortly after it rotated into the view of NASA’s Solar Dynamics Observatory, or SDO. Much of the solar material did not escape the sun’s gravitational pull, falling back to the solar surface.

Source:http://www.nasa.gov/feature/goddard/2016/nasa-s-sdo-sees-circular-outburst

Reference:http://sunearthday.nasa.gov/2007/locations/ttt_prominences.php