A telescope so cool that it stars in its own movie has made a discovery that really has astronomers scratching their heads – powerful radio bursts from deep in the Universe.
The strange signals last only a fraction of a second and no one yet knows what is causing them.
The telescope is the Parkes 64-metre radio telescope in Australia which was the centrepiece of a mainstream comedy movie called The Dish in 2000.
Five of the flashes, lasting just milliseconds have been recorded in the past six years but in just a tiny part of the sky. This suggests that they are happening somewhere in the sky every few seconds.
What astronomers are fairly certain of is that the signals were caused by cataclysmic events far outside our own galaxy, at cosmological distances of billions of light-years and when the Universe was around half its present age.
Suggestions for their cause include highly energetic sources such as neutron stars, including an exotic type called magnetars, or black holes. But such suggestions are pure guesswork at the moment.
Skymania caught up with Prof Albert Zijlstra, Director of the Jodrell Bank Centre for Astrophysics, at the Royal Astronomical Society’s National Astronomy Meeting at St Andrews, Scotland, just after we had both been to a session about looking for ET.
“Perhaps it is the aliens,” he quipped. But he added: “We have no idea what these are. They are a complete mystery.”
The strange discovery, announced in the journal Science, was made by an international team led by Dan Thornton, a PhD student at England’s University of Manchester and Australia’s Commonwealth Scientific and Industrial Research Organisation.
Dan said: “A single burst of radio emission of unknown origin was detected outside our Galaxy about six years ago but no one was certain what it was or even if it was real, so we have spent the last four years searching for more of these explosive, short-duration radio bursts.
“This paper describes four more bursts, removing any doubt that they are real. The radio bursts last for just a few milliseconds and the furthest one that we detected was several billion light years away.”
A video about the mysterious radio bursts. Credit: Swinburne Astronomy Productions
Amazing as it seems, astronomers are suggesting that these previously unknown flashes are likely to be occurring every 10 seconds. Max-Planck Institute Director, co-author and Manchester professor, Michael Kramer, said: “The bursts last only a tenth of the blink of an eye. With current telescopes we need to be lucky to look at the right spot at the right time. But if we could view the sky with ‘radio eyes’ there would be flashes going off all over the sky every day.”
Professor Matthew Bailes, of the Swinburne University of Technology in Melbourne, thinks the origin of these explosive bursts may be from magnetic neutron stars, or ‘magnetars’. He said: “Magnetars can give off more energy in a millisecond than our Sun does in 300,000 years and are a leading candidate for the burst.”
The researchers say their results will also provide a way of finding out the properties of space between the Earth and where the bursts occurred.
Dr Ben Stappers, from Manchester’s School of Physics and Astronomy, said: “We are still not sure about what makes up the space between galaxies, so we will be able to use these radio bursts like probes in order to understand more about some of the missing matter in the Universe. We are now starting to use Parkes and other telescopes, like the Lovell Telescope of the University of Manchester, to look for these bursts in real time.”
The discovery team included astronomers from the UK, Germany, Italy, Australia and the United States.