The newly detected signal, named GLEAM-X J0704-37, emits a pulse of energy every three hours, lasting up to a minute, making it the longest-period radio transient ever observed.
Astronomers have made a fascinating breakthrough, decoding a cosmic mystery that has puzzled scientists for years. A rare phenomenon known as long-period radio transients—bright energy bursts from space occurring at unusually long intervals—has been studied in unprecedented detail, leading to a possible explanation for their origin.
Led by Associate Professor Natasha Hurley-Walker from Curtin University’s International Centre for Radio Astronomy Research (ICRAR), the team made this groundbreaking discovery while analyzing archived data from the Murchison Widefield Array (MWA), a state-of-the-art radio telescope in Western Australia. The newly detected signal, named GLEAM-X J0704-37, emits a pulse of energy every three hours, lasting up to a minute, making it the longest-period radio transient ever observed.
The First Clear View of a Rare Phenomenon
Unlike previous discoveries buried within the dense core of our galaxy, this signal was located in a quiet region of space near the Puppis constellation, about 5,000 light-years away. This relatively empty area provided astronomers with a clear line of sight to investigate its source.
“This is a rare opportunity,” explained Hurley-Walker. “Most long-period transients are hidden among countless stars, making it incredibly challenging to identify their origins. But this one sits far off the galactic plane, allowing us to narrow down the source.”
The team used South Africa’s MeerKAT telescope to trace the signal to a specific star system. Follow-up observations with Chile’s SOAR telescope revealed that the system contains an M dwarf star, a small, dim type of star that is invisible to the naked eye but makes up 70% of the stars in the Milky Way.
A Surprising Binary Pair
However, the energy emitted by the M dwarf alone couldn’t account for the intense radio pulses. Astronomers determined that the star is likely part of a binary system, paired with a white dwarf, the dense remnant of a once-larger star. Together, this stellar duo produces mysterious bursts of energy.
“This is the first time we’ve linked an M dwarf and a white dwarf to long-period radio transients,” said Hurley-Walker. “It’s a major step in understanding these extraordinary phenomena.”
Interestingly, the GLEAM-X J0704-37 signal has been active for at least a decade, as revealed by data from the MWA’s 55-petabyte archive. This massive database, described as a “gold mine” by MWA Director Professor Steven Tingay, contains a decade of observations and remains a rich resource for future discoveries.
“The MWA has fundamentally enabled these breakthroughs,” Tingay said. “Its extensive archive provides astronomers with an incredible opportunity to uncover hidden phenomena and expand our knowledge of the universe.”
With follow-up observations already underway, the research team hopes to fully decode the mechanics behind this enigmatic binary system and uncover more transients hiding in plain sight.