This close-up image of the Sun was taken on April 24, 2013 at 12:02 pm. The telescope filters out all colors except for one shade of red light, called Hydrogen-alpha. This reveals the atmosphere of the Sun, which is called the chromosphere.
The "star" on the Sun this week has been the sunspot group AR 1726, visible here near the edge of the Sun. The magnetically active region is more than twelve times as wide as the Earth, and has been crackling with low-level solar flares all week. It still has the potential to produce a major flare.
The dark dots are sunspots, which are cooler regions of intense magnetic activity on the surface of the Sun. They are partially veiled by the bright clouds suspended above the middle of the sunspot group. These clouds are called plages, and can glow brightly when a solar flare occurs.
Telescope: Lunt 100mm Hydrogen-alpha
Camera: Lumenera SKYnyx 2-2M
Image Number: WEB12841-2013
Credit: Image by Geneviève de Messières, Smithsonian Public Observatory Project
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