Scientists have discovered a strange star system more than 5,000 light-years from Earth that emits mysterious radio signals every eight minutes. The signals come from a system containing a dead star that spins once every eight minutes and orbits another star every 32 hours.
The newly discovered system, called GPM J071507−114153, contains a white dwarf, the dense remains of a dead star, and a G-type star that is similar to our Sun.
According to researchers at Curtin University, this is the first time radio pulses have been detected from a white dwarf orbiting a Sun-like star. The discovery, published in the journal Nature Astronomy, could help explain other mysterious radio signals astronomers have studied for years.
Among those mysterious radio signals astronomers have previously discovered are an unknown source that has been transmitting radio signals for 35 years, a mysterious heartbeat-like radio signal, and radio emissions from a distant planet.
Scientists May Have Solved One Mystery Surrounding Radio Signals From Space
These new signals belong to a group of astronomical objects called long-period transients (LPTs), which emit radio pulses at intervals ranging from minutes to hours. Only about a dozen have been discovered since 2021, when the same research team identified the first one.
While scientists have previously found similar systems containing white dwarfs, they haven’t been able to determine which star was producing the signals.
“This is the first time the pulses are clear enough to see the white dwarf moving in its orbit around its companion,” said lead researcher Dr. Sam McSweeney.
Researchers analyzed more than 100 hours of radio data using the Pawsey Supercomputing Research Centre. They also used radio telescopes in Australia and South Africa, as well as the Keck Observatory in Hawaii, to identify the system.
The observations indicate that the signals originate near the white dwarf, possibly from the star itself.
Researchers Also Detected Massive Stellar Storms
While studying the signals, scientists discovered something else. They detected stellar flares and evidence of a massive plasma loop extending from the Sun-like star, similar to the activity that produces Earth’s auroras.
“It’s amazing that by using radio wavelengths we can detect the storms on a star over 5,000 light-years away,” said researcher Natasha Hurley-Walker.
Scientists still haven’t determined exactly what produces the pulses in this latest system.
However, researchers believe the next generation of radio telescopes will help them discover more of these unusual stellar pairs and possibly explain how the signals are generated.
“If we are already making such discoveries with precursor telescopes, just imagine how many more star systems we will be able to find, and what a beautifully detailed view of their signals we will have, once the SKAO [Square Kilometre Array Observatory] telescopes are completely built,” said Dr. McSweeney.