杏吧原创

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OUT, damned spot! The largest sunspot in 25 years is about to slide off the face of the sun and out of sight. The catchily named spot 鈥� Active Region 12192 鈥� has been a wild one, spawning six large solar flares that knocked out radio communications across swathes of the planet last week. If it is still active by the time it rotates back to our side of the sun, it will thankfully be a shadow of its former self.

In this image, taken at the shortest wavelengths the human eye can see, near the ultraviolet end of the spectrum, AR 12192 is dark because it is relatively cool. It鈥檚 a mere 3000 掳C, compared with the 5500 掳C blaze of the surrounding photosphere. Powerful magnetic fields twisted beneath the sun鈥檚 surface stymie the star鈥檚 normal convective heating.

鈥淭his time of year I have to wait for the sun to get up past a whole bunch of cable TV wires and electrical poles, so it鈥檚 11 o鈥檆lock before I can see it,鈥� says astrophotographer , based in Buffalo, New York. 鈥淢akes it hard to have a day job too.鈥�

Friedman used a filter made of calcium to block out a large component of the sun鈥檚 light, making it resemble a ghostly, volcanic ping pong ball, or perhaps a human egg cell.

For Friedman, photos are the only way to reveal this view of the sun: 鈥淲hen I look through the telescope I can鈥檛 see a thing at that wavelength. As your eyes get older and more yellow they block the higher wavelengths. But the camera can still see well.鈥�

This article appeared in print under the headline 鈥淪unny and flare鈥�