![]() ![]() Follow-up observations were with the South African Radio Astronomy Observatory's MeerKAT telescope. Mr Wang and an international team, including scientists from Australia's national science agency CSIRO, Germany, the United States, Canada, South Africa, Spain and France discovered the object using the CSIRO's ASKAP radio telescope in Western Australia. The discovery of the object has been published today in the Astrophysical Journal. But the signals from this new source don't match what we expect from these types of celestial objects," Mr Wang said. "At first we thought it could be a pulsar - a very dense type of spinning dead star - or else a type of star that emits huge solar flares. Pulsars, supernovae, flaring stars and fast radio bursts are all types of astronomical objects whose brightness varies. With tremendous advances in radio astronomy, the study of variable or transient objects in radio waves is a huge field of study helping us to reveal the secrets of the Universe. Many types of star emit variable light across the electromagnetic spectrum. "The brightness of the object also varies dramatically, by a factor of 100, and the signal switches on and off apparently at random. This means its light oscillates in only one direction, but that direction rotates with time," said Ziteng Wang, lead author of the new study and a PhD student in the School of Physics at the University of Sydney. While Dr Dobie agreed the object was not like magnetars we've found in the past, he said it was hard to come to any conclusions about the source just based on one discovery.īut, he added, now we've found one of these things using this new technique, we know how to find more."The strangest property of this new signal is that it is has a very high polarisation. "There are lots of things we've discovered with the MWA and other radio telescopes that have been 'it's just a matter of time before we detect this kind of thing', but this has come completely out of nowhere," Dr Dobie said. 'Completely out of nowhere'ĭougal Dobie, an astrophysicist at Swinburne University of Technology not involved with the project, said the discovery was exciting. "And then there's a small chance that it's just something we've never even thought of."ĭespite searching across more than seven years of data from the MWA and following up with other radio telescopes, the mysterious object was not detected either before or after the three-month period in 2018.īut Dr Hurley-Walker and her team are continuing to follow up with observations with other telescopes such as the Chandra Space Telescope and, hopefully, Hubble, which could detect if there is a white dwarf in the area. While an ultra-long period magnetar is currently the team's best bet, another option is a white dwarf pulsar that developed sunspots, which bumped up its magnetic field.īut that is less likely according to Dr Hurley-Walker because unlike neutron stars, white dwarfs can be seen in optical and ultraviolet light so it should have been previously detected. "We've predicted that these things would exist, but nobody expected them to be detectable." that has become twisted or tangled," Dr Hurley-Walker said. ![]() "So what we think this is is it's either a neutron star or a white dwarf star that has a strong magnetic field. Most repeating sources such as pulsars - fast-spinning cores of dead stars - flash on and off within a matter of milliseconds or seconds.īut what sets this new source apart is that each flash is separated by 18 minutes. The sky is packed with radio transients, objects that produce pulses of radio emissions that appear and disappear. "And it's just in our galactic backyard." Unlike anything discovered before – or since "All the evidence was coming in that we had a new type of radio transient that was repeating really regularly and was stunningly bright, which sort of begs the question: how did people miss these before?" Dr Hurley-Walker said. "I kept going back in time and finding it over and over again," Dr Hurley-Walker said.Īll the pulses lined up with an 18-minute interval, so she could predict when she would see it appear in the data.Īnalysis of the pulses ruled out artificial sources such as aliens (seriously) or interference by Earth-based technologies. I wasn't aware of how significant it would be," he said.Īfter trawling through more data, the team detected 70 pulses of radio energy coming from the object at various times throughout the three-month period at the beginning of 2018.
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