Transplant heroine refines mystery at astronomy's heart

Astronomers reckon a typical 'fast radio burst' releases as much energy in a millisecond as the Sun puts out in three days.

Yet the strength of these distant, transient signals as they reach Earth is something like 1000 times weaker than what a mobile phone would emit from the Moon.

It makes them at once awe-inspiring but excruciatingly hard to find and, until now, almost impossible to explain.

Thanks to the efforts of a young astrophysics student in Australia's remote west, however, science is on the verge of uncloaking one of space's most exciting and mysterious phenomena.

And she did it while unknowingly suffering from a heart condition that required a life-saving transplant.

First described in 2007, fast radio bursts (FRBs) have been linked to everything from black holes to extraterrestrial intelligence.

More plausibly, it's been suggested they're caused by the merging of incredibly dense remnants of exploding celestial bodies known as neutron stars.

Yet the idea was more speculation than substance until Alex Moroianu produced the smoking gun. 

Part of an international research team, the 24-year-old University of Western Australia postgrad searched events detected by gravitational wave interferometers in the United States and Italy, along with a catalogue of fast radio bursts released by a radio telescope in Canada.

She found a neutron star merger and a fast radio burst had occurred on April 25, 2019 at the same time and distance, and in the same part of the sky.

It was a one-in-200 chance coincidence.

"This is extremely exciting and would certainly help unravel some of the mystery surrounding these fast radio bursts, such as why repeating and non-repeating bursts exhibit different properties," she said.

"If our observation is confirmed by further evidence in the future, it implies multiple origins for fast radio bursts."

Incredibly, Ms Moroianu's groundbreaking discovery occurred as her heart was inexplicably failing. She submitted the research paper while in hospital waiting for a transplant in early 2022.

"It was definitely a difficult time but it made me stronger in the end," she said.

Her condition was diagnosed as lymphocytic myocarditis and she was one of just a handful of Australians to receive a new heart via a specially-designed transportable device that pumps the donor organ with blood, oxygen and nutrients. 

Curtain University's Dr Clancy James, who co-supervised the FRB study, said Ms Moroianu's findings were "incredibly significant".

"This may be the clue that solves the mystery of what is producing fast radio bursts and tells us what the super-dense matter found in neutron stars is actually like," he said.

"The result is not conclusive but it's the 'smoking gun' that will point the way for future studies."