Alan Bellows says "There's a town in New Mexico called Sunspot, and it's home to one sweet piece of optical hardware: the National Science Foundation's Dunn Solar Telescope. Last month it snapped a gorgeous photo of a sunspot, which is an area that is relatively cool and dim on the sun's surface, but bristling with magnetic activity. This particular sunspot was more than three times wider than the Earth.
"The level of clarity was achieved using the Dunn's freshly installed advanced adaptive optics image correction system and a new high-resolution digital camera. Usually Earth's writhing atmosphere causes too much distortion for ground-based telescopes to capture so much detail, but the Dunn compensates for this with a spiffy deformable mirror that changes its shape 130 times per second to maintain optimal focus. It also uses a system where it takes a large number of images in quick succession, almost 30 per second for several seconds, then uses sophisticated software to combine all of the best parts from all of the images into one high-clarity finished product."
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