Solar Prominences, July 28, 2012. This photograph was taken with a hydrogen alpha scope that only shows one wavelength of light, at 656.3 nanometres. This is the particular wavelength of hydrogen alpha light. Observing the Sun in hydrogen alpha makes it possible to see structural details.
Large prominences of plasma lift off the surface of the Sun at tremendous speeds, and they are most easily seen along the edge with the darkness of space behind them. These moderately large prominences, held aloft by an immense magnetic arch, are many times larger than the Earth. The flame-like structure in the lower left corner is a solar filament, tens of thousands of kilometres long. A filament is the same as a prominence, but as seen from the top down. The patchy, circular pattern between the filament and the prominences is caused by powerful magnetic fields surrounding some small sun spots.
This photograph was featured in the October 2012 issue of the Journal of the Royal Astronomical Society of Canada, and on the Canadian Geographic website.
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