2014年11月16日 星期日

Epic 4K Sun Video, with Bonus Sunspot Tantrums

Not long ago, the ridiculously huge sunspot called Active Region 2192 ruled the face of the Sun. Bigger than Jupiter, it was easily seen by the (adequately protected) naked eye, and it was a distracting though extremely cool blemish during October’s solar eclipse.


A sunspot that big has a lot of storage space to stuff magnetic fields, and 2192 didn’t disappoint. Sunspots are essentially magnetic phenomena, and as the huge looping magnetic field lines in the spot tangled up, they sometimes violently snapped and reconnected, releasing their energy as solar flares. Dwarfing every nuclear bomb on Earth combined, the flares kept popping off as 2192 marched across the Sun’s disk, swept along with our star’s rotation.


From space, the Solar Dynamics Observatory keeps a close eye on the Sun, and watched in multiple wavelengths (think of them as colors) as 2192 did its thing. James Tyrwhitt-Drake, who has created interested scientific animations before, took 17,000 SDO images of the Sun in the ultraviolet, spanning Oct. 14 – 30, 2014, and created an astonishing video that shows 2192 in all its glory. The video is available in 4k resolution, if your bandwidth can choke that down, but it’s worth it to make this full screen:


The sound you hear is not real; it’s made from visible light data by SDO’s Helioseismic and Magnetic Imager, which maps motions on the Sun’s surface, which was then converted into sound by solar astronomer Alexander Kosovichev.


In this view, south is up, so the Sun rotates right to left (I’m used to it the other way, but hey, in space there is no up, so fine). 2192 makes its appearance early on, announcing its presence with towering loops of magnetic energy over 200,000 km high — mind you, the Earth is a mere 13,000 km across — and dominates the view thereafter. It’s incredible.


You can watch as enormous prominences erupt away from it, hot hydrogen gas flowing along otherwise invisible magnetic field lines like beads on a wire. The gravity of the Sun is strong, and pulls the gas with a force nearly 30 times stronger than Earth’s gravity, but the magnetic field is strong, too, and the gas flows back to the Sun along curving, graceful paths. It’s mesmerizing.


As the Sun rotates, AR 2192 has come around again, returning on or about Nov. 12. But it decayed substantially when it was on the far side of the Sun from the Earth. It’s a shadow, so to speak, of its former self. It doesn’t look like it’ll last much longer. We may not get another spot like it for a long time; it was the biggest seen in decades. But the Sun is a complex beast, and predicting its behavior for things like this is a losing bet. We may not see another like 2192, or another might grow and swell into existence once again. We’ll have to wait and see.






from Bad Astronomy http://ift.tt/11sLjL7

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