Astronomers might have decoded a mysterious signal from space. Something in the universe is sending powerful, regular bursts towards Earth – and now researchers think they have decoded what it is.
Breakthrough in Understanding Cosmic Signals
Scientists think they might have decoded the origin of some of the most mysterious and powerful signals coming from space. Researchers have long been puzzled by “long-period radio transients”, which send out regular powerful blasts of radio waves and X-rays on a repeating 1.4 hour tempo. They seem to come from only a few remote parts of our galaxy.
Now researchers believe they have tracked down their source: a small, dense star called a white dwarf that is pulling material from its larger and less dense companion star. The material spirals in and produces the blasts, researchers believe.
“For the first time we have pinpointed the origin of these signals, confirming the source to be a ‘cataclysmic variable’, or an accreting white dwarf star,” said Kovi Rose, a PhD student at the University of Sydney who led the discovery. “Long-period radio transients have puzzled astronomers for years. We’ve only found about a dozen, and their origins have been unclear. Now, we’ve been able to show that the source for one of these transients comes from a white dwarf actively pulling material from a companion star.”
The System Behind the Signals
The system found in the study, named ASKAP J1745−5051, is made up of the two stars, orbiting each other extremely closely. As they interact, the material from the latter star is heated up and sends out X-rays, and the two stars’ magnetic fields produce the regular radio bursts.
Previously, researchers have thought the blasts would be coming from slow-spinning neutron stars known as pulsars. But newer work has suggested that stars rotating so slowly should not be able to produce such signals. Scientists hope that the work will also prove to be a useful way of understanding other such signals, by helping to decode them.
The work is reported in a new paper, ‘Periodic radio and X-ray emission from an accreting white dwarf binary’, published in the journal Nature Astronomy.
