Scientists at Curtin University have found the source of strange radio signals from space. A new study in The Astrophysical Journal Letters says these signals come from two stars orbiting each other, including a red dwarf, according to the university’s International Centre for Radio Astronomy Research (ICRAR).
Associate professor Natasha Hurley-Walker and student Csanád Horváth first discovered a strong energy pulse from deep space, according to findings published in the scientific journal Nature in January 2022. Using old data from the Murchison Widefield Array (MWA), a special telescope in Australia, they now have found the source of the pulse.
According to an ICRAR press release last week, the pulse happens every three hours and lasts up to a minute. Researchers say it’s now the longest-lasting radio signal ever found.
“The long-period transients are very exciting, and for astronomers to understand what they are, we need an optical image. However, when you look toward them, there are so many stars lying in the way that it’s like 2001: A Space Odyssey. ‘My god, it’s full of stars!’,” Hurley-Walker said.
The new signal, called GLEAM-X J0704-37, was found in a fairly empty part of space about 5,000 light years away. It’s in an area of stars called Puppis. This helped the scientists figure out which star was making the radio waves, according to the press release.
Using telescopes in South Africa and Chile, the team found that the star is an M dwarf—also called a red dwarf—which is a small, cool star. But Hurley-Walker said an M dwarf by itself could not produce this much energy.
“The M dwarfs are low-mass stars that have a mere fraction of the Sun’s mass and luminosity. They constitute 70 per cent of the stars in the Milky Way, but not one of them is visible to the naked eye,” she said.
The scientists think the M dwarf is paired with another star called a white dwarf. Together, they might be making the radio signal. They plan to do more research to check this hypothesis, ICRAR reported.
Finding GLEAM-X J0704-37 could lead to more discoveries. The signal has been active for at least ten years, which means there might be more hidden signals in old space data around the world, according to the researchers.
Professor Steven Tingay from ICRAR said the MWA radio telescope’s big data collection is important for making these discoveries.
“The MWA has a 55-petabyte archive of observations that provide a decade-long record of our Universe. It is like having the data storage equivalent of 55,000 high-end home computers – one of the biggest single collections of science data in the world. It is an absolute gold mine for discovering more phenomena in our Universe, and the data are a playground for astronomers,” Tingay said.
This research, published Dec. 1 in the Astrophysical Journal Letters, helps researchers understand long-lasting radio signals better and opens up new ways to explore space mysteries, ICRAR says.