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The Explosion that Rocked the Universe

By David Reneke

The launch of a revolutionary Australian instrument will enable the fastest-ever survey of stars in our galaxy.

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It was one of the most powerful explosions ever seen, and it echoed right across the visible universe. Recently, an international team of 31 astronomers, led by the University of Maryland’s Eleanora Troja and Nathaniel Butler from Arizona State University, caught a massive star as it died in a titanic explosion deep in space.

The blast of the dying star released in about 40 seconds as much energy as the Sun releases over its entire lifetime, all focused into a tight beam of gamma rays aimed by chance toward Earth. The team’s findings, using two purpose-built NASA satellites, provide strong evidence for one of two competing models for how gamma-ray bursts produce their energy. These are the brightest explosions in the universe, allowing astronomers to record the development and decay almost from the initial blast. The satellite observatories detected the burst of gamma rays, identified where in the sky it came from, and sent its celestial position within seconds to automated telescopes on the ground.

While gamma-ray bursts have been known for about 50 years, astronomers are still mostly in the dark about how they erupt. “Despite a long history of observations,” Butler says, “the emission mechanism driving gamma-ray bursts remains largely mysterious, but the magnetically driven model is gaining favour”.

Gamma-ray bursts are detected approximately once...

The full text of this article can be purchased from Informit.