clipped from: space.newscientist.com   

Jets of matter clocked at near-light speed


The fastest flows of matter in the universe shoot out of dying stars at more than 99.999% the speed of light, new observations reveal.


When a massive star runs out of fuel, it collapses to form a black hole or a neutron star. In the process, some of the matter from the star also explodes outwards at blistering speeds, producing an intense burst of gamma rays and other radiation.


Scientists had predicted that the matter expanding in these explosions would be propelled to very nearly the speed of light, but it has previously not been possible to clock them precisely.


Now, rapid follow-up measurements of two gamma-ray bursts have allowed a team of scientists to precisely measure the expansion speed of matter in these explosion to more than 99.999% the speed of light. The team was led by Emilio Molinari of the Osservatorio Astronomico di Brera in Merate, Italy.