Scientists have finally unscrambled the mystery of repeating cosmic signals that have perplexed astronomers for many years.
An international team, led by the University of Sydney, found the signals were linked to a dwarf star sending powerful bursts of radio waves and X-rays in a cycle that repeats every 1.4 hours.
The discovery has been described as a “Rosetta stone” for future discoveries
Lead study author and PhD student Kovi Rose, from the University of Sydney’s School of Physics and CSIRO, said the work marked the first confirmed identification of “long-period radio transients”.
These were cosmic pulses discovered from just a few remote regions of our galaxy.
“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,” Mr Rose said.
“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 findings are published in Nature Astronomy.
The team found that the radio emission probably originated where the magnetic fields of two stars meet and interact with the charged material being ripped from the companion star, producing “tightly beamed” bursts of radiation.
Long-period radio transients were initially thought to be slow-spinning neutron stars, known as pulsars.
However, current models suggest neutron stars rotating this slowly should not be able to produce such signals.
The international team included astronomers from the United States, China, Canada, Spain, Israel and Australia.
The team used CSIRO’s Australia Telescope Compact Array and ASKAP radio telescopes in Australia, the MeerKAT radio telescope in South Africa, the SOAR and Magellan optical telescopes in Chile, and the space-based Swift (UV/X-ray) and Einstein Probe (X-ray) telescopes. The full report is available here.
