A deep space radio signal called ‘Lorimer burst’ has remained a mystery for quite some time. It was originally discovered back in 2007 after analyzing a sky survey that was taken in 2001. The incredibly powerful radio signal flashed very bright for around five milliseconds and then disappeared. The astronomers later found that whatever was behind sending this blast of radio waves must have been around 3 billion light years away, in another galaxy.
More and more of these signals have been detected over the past few years, with one detector capturing one of these bursts once every day on average. Each of these bursts come from single events that occurred billions of light years away, but as to where the source is exactly, remains a mystery. What astronomers do know is that they must be caused by a cataclysmic astronomical event of some description, but are unable to pinpoint what exactly.
One theory is that it’s because of a ‘magnetar’ (a magnetic neuron star). When a star that’s much bigger than our Sun dies, a neuron star is what remains. It tends to be around 20 kilometers or so in diameter and incredibly dense. Some of these stars throw off beams of radiation, called pulsars, as they spin around very quickly. A magnetar, on the other hand, spins much slower and is extremely magnetic. Professor Matthew Bailes is the director of the Swinburne Centre for Astrophysics and Supercomputing, Melbourne, and he says, “These are the most magnetic stars in the universe, and now and then they have very large explosions on them, which may be a good candidate for the origin of these things.”
Another fantastic thing about these bursts is that they carry so much information about the universe with them. “Every time the radio waves go past an electron, the electron’s presence gets encoded in the burst of photons. We can use this to count how many electrons there are between us and half way across the universe, which is incredibly exciting because almost all of the ordinary atoms are not in galaxies, they’re just sitting around in the intergalactic medium,” Bailes commented. Now it’s a case of putting all the information together that’s been gathered in order to help us better understand more about some of the missing matter in the universe.