This picture of the Sun was taken at 1:03 pm on June 16, 2012, shortly after the Public Observatory opened for the afternoon. On-site and online visitors observed a beautiful arcing prominence, seen at the lower right of this image.
The prominence is a loop of gas above the Sun. The Sun is so hot that its gas is partially ionized: some electrons have been stripped from their atoms. This kind of gas must follow magnetic field lines. Magnetic loops that protrude from the Sun therefore serve as highways above the surface of the Sun. Gas streams along the loops, creating prominences, and then usually falls back into the Sun.
Also visible in this image is the dramatic sunspot group A.R. 1504, a cluster of three dark dots near the center right of the Sun. Each sunspot is about twice as large as the Earth. This sunspot group has been producing moderate flares and has the potential to produce more extreme flares.
Telescope: Lunt 100mm hydrogen-alpha
Camera: Lumenera Skynyx 2-2M
Image Number: WEB12502-2012
Credit: Image by Geneviève de Messières, Smithsonian Public Observatory Project
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