SYDNEY, June 2 (Xinhua) -- Astronomers have identified the clearest evidence for the origin of mysterious cosmic signals, linking them to a rare binary star system that offers a natural laboratory for extreme physics.
Using Australia's ASKAP radio telescope, a University of Sydney-led team discovered a white dwarf star shredding material from its larger, less dense companion red dwarf. The system, named ASKAP J1745-5051, produces powerful radio and X-ray bursts every 1.4 hours, according to a university statement released on Monday.
The discovery marks the first confirmed identification of so-called long-period radio transients, previously observed in only about a dozen locations in our galaxy, said Kovi Rose from the University of Sydney, lead author of the study published in Nature Astronomy.
As material from the companion star spirals toward the dense white dwarf, it emits X-rays, while interactions between the stars' magnetic fields generate regular radio bursts. The radio and X-ray signals do not peak simultaneously, indicating they originate in different regions of the system, Rose said.
Scientists had earlier suggested long-period radio transients were slow-spinning neutron stars, but the new findings support an alternative explanation involving accreting white dwarfs.
The system could serve as a "Rosetta stone" for interpreting similar signals, Rose said, likening it to the ancient Egyptian artifact that unlocked hieroglyphics.
The discovery by the international team, comprising researchers from Australia, the United States, China, Canada, Spain, and Israel, also offers insights into extreme plasma physics and magnetic interactions under conditions impossible to replicate on Earth.
"These systems are natural laboratories. They allow us to test our understanding of how matter behaves in strong magnetic fields and under intense gravitational forces," Rose said. ■
