Bright spots and illuminated arcs of solar material hovering in the sun's atmosphere highlight what's known as "active regions" on the sun.
Bright spots and illuminated arcs of solar material hovering in the sun’s atmosphere highlight what’s known as active regions on the sun, in this image from NASA’s Solar Dynamics Observatory, captured on April 20, 2015. These are areas of intense and complex magnetic activity that can sometimes give rise to solar eruptions such as solar flares and coronal mass ejections. Credit: NASA/SDO