This close-up image of the Sun was taken on July 12 at 12:56 pm, during a powerful X1.4-class solar flare.
A solar flare is a flash of high-energy light. It is created when magnetic fields on the surface of the Sun slam together, releasing vast amounts of energy. The ultraviolet and X-ray light created by a flare does not penetrate the Earth's atmosphere, and cannot be seen by human eyes anyway. A visitor looking through any of the safe solar telescopes at the Observatory would not see the light of a flare.
However, the light of a flare heats up the gas around it, which we can see. The July 12 flare happened in the massive sunspot group 1520, visible as a cluster of dark spots. A plage is a cloud of gas above a sunspot region, often glowing brightly in red light. The flare heated up the plages around the sunspots. The plages are what we see glowing brilliantly in this image.
While a flare poses no direct threat to life on Earth, it can increase radiation for astronauts. When the light of the flare is absorbed by the atmosphere, the outer layers of the atmosphere heat and puff up, disrupting radio communications and GPS signals.
Telescope: Lunt 100mm
Camera: Lumenera SkyNYX 2-2M
Image Number: WEB12540-2012
Credit: Photo by Geneviève de Messières, Smithsonian Public Observatory Project
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