Thermit
Site Admin
Joined: 11 Aug 2004
Posts: 272
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| Brightest Galactic Flash Ever Detected Hits Earth |
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By Robert Roy Britt
Senior Science Writer
posted: 18 February, 2005
2 p.m. ET
A huge explosion halfway across the galaxy packed so much power it briefly altered Earth's upper atmosphere in December, astronomers said Friday.
No known eruption beyond our solar system has ever appeared as bright upon arrival.
But you could not have seen it, unless you can top the X-ray vision of Superman: In gamma rays, the event equaled the brightness of the full Moon's reflected visible light.
The blast originated about 50,000 light-years away and was detected Dec. 27. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).
The commotion was caused by a special variety of neutron star known as a magnetar. These fast-spinning, compact stellar corpses -- no larger than a big city -- create intense magnetic fields that trigger explosions. The blast was 100 times more powerful than any other similar eruption witnessed, said David Palmer of Los Alamos National Laboratory, one of several researchers around the world who monitored the event with various telescopes.
"Had this happened within 10 light-years of us, it would have severely damaged our atmosphere and possibly have triggered a mass extinction," said Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics (CfA).
There are no magnetars close enough to worry about, however, Gaensler and two other astronomers told SPACE.com. But the strength of the tempest has them marveling over the dying star's capabilities while also wondering if major species die-offs in the past might have been triggered by stellar explosions.
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http://www.space.com/scienceastronomy/bright_flash_050218.html
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