In identifying an unusual stellar binary system, an international team led by astronomers at the University of Sydney and CSIRO has uncovered the strongest evidence yet for the origin of mysterious cosmic signals.

The new source of repeating radio bursts, called ASKAP J1745, was discovered to be a small, dense star, called a white dwarf, shredding material from its larger, but less dense, companion star.

As this material spirals in, it produces powerful bursts of radio waves and X-rays in a cycle that repeats every 1.4 hours.

The findings were published in Nature Astronomy.

Lead author and PhD student Kovi Rose from the University of Sydney’s School of Physics and CSIRO said this provides the first confirmed identification of long-period radio transients. For the first time the origin of these signals has been pinpointed, confirming the source to be a ‘cataclysmic variable’, or an accreting white dwarf star.

ASKAP J1745 is exciting because, unlike 10 of the 12 known long-period transients, its origins are now known. The team was able to detect it with many different telescopes that observe all different kinds of light.

Bearing the same message in three forms of writing, the famous Rosetta stone once helped scholars decipher ancient Egyptian hieroglyphs. Similarly, this extra information found about ASKAP J1745 will help astronomers better understand the mystery of all long-period transients.

Read more on CSIRO’s website.

An illustration showing a large orange sphere on the left and a much smaller bright object on the right, surrounded by dense looping white lines. A glowing, curved blue-green line goes from the large sphere to the smaller object. The background is dark teal with scattered tiny white specks.

An illustration of an accreting white dwarf (Image credit: Carl Knox (OzGrav, Swinburne University of Technology) and Joshua Preston Pritchard (CSIRO).