What is the Brightest Flash Ever Detected?
The brightest flash ever detected was observed on 27 December 2004. Its source was a magnetar, a form of neutron star with a powerful magnetic field and mass greater than the sun condensed into an area the size of a small city. With emissions primarily in the gamma ray portion of the spectrum, this explosion released more energy in a tenth of a second than the Sun produces in 100,000 years. The magnetar is located 50,000 light years away, about half the distance across the galaxy. If the explosion, not just the brightest flash of the century, but possibly the last thousand years of galactic history – occurred within 10 light years of the Earth, it could have stripped off the atmosphere and caused a mass extinction. The precise cause of the explosion is still unknown. Imagine a sphere 20 km (12 mi) across, so massive that each teaspoonful of its material weighs two million tons, rotating once every 7.5 seconds, with a magnetic field so strong it can wipe a credit card at the distance of
