It’s unlike anything we’ve seen before in space. A team of scientists mapping radio waves in the universe has discovered, using Australia’s Murchison Widefield Array (MWA) telescope, an unusual object that releases a colossal burst of energy three times an hour (for 1 minute in 20), becoming one of the brightest points in the sky at that time.
Although it is one of the brightest radio objects in the sky for this minute , it went unnoticed by astronomers until this team discovered it by reviewing data collected by the telescope located in the outback of Western Australia.
” When it’s on, it’s brighter than the next brightest thing in the sky in that area, which is a supermassive black hole [millions of light-years away],” said Natasha Hurley-Walker, an astrophysicist at Curtin University. and the International Center for Radio Astronomy Research.
What could this mysterious energy source be?
A supernova? Two stars colliding? Astronomers think that GLEAM-X J162759.5-523504.3, as it has been named, could be a neutron star or a white dwarf (the collapsed core of a star) with an ultra-strong magnetic field, also known as a magnetar.
“This object appeared and disappeared for a few hours during our observations,” continued Hurley-Walker of the Curtin University node of the International Center for Radio Astronomy Research (ICRAR) in Australia. “That was completely unexpected. It was a bit spooky for an astronomer because there’s nothing known in the sky that does that. And it’s really quite close to us, about 4,000 light-years away. It’s in our galactic backyard.”
So what is it? It is very likely that it is one of these two theories: either a neutron star or a magnetar. If the former, it would be the first time we have detected a magnetar with a very long pulsation period, known as an ultra-long-period magnetar.
The objects that turn on and off in the universe are not new to astronomers, they call them “transients”. There are “slow transients ,” like supernovae, that can appear over the course of a few days and disappear after a few months, and “fast transients ,” like a type of neutron star called a pulsar, that turn on and off in milliseconds. or seconds.
Perhaps the balance tips more towards a magnetar whose magnetic field is spectacularly powerful?
Researchers are now monitoring the object to see if it ‘turns on’ again and “further detections will tell astronomers if this is a rare, single event or a large new population that we’ve never seen before,” concludes Gemma Anderson. , co-author of the work published in the journal Nature.
MWA Director Professor Steven Tingay said the telescope is a precursor instrument to the Square Kilometer Array, a global initiative to build the world’s largest radio telescopes in Western Australia and South Africa.
Referencia: Hurley-Walker, N., Zhang, X., Bahramian, A. et al. A radio transient with unusually slow periodic emission. Nature 601, 526–530 (2022). https://doi.org/10.1038/s41586-021-04272-x