Astronomers have discovered a pulsar – a dense, fast-spinning neutron star sending radio waves into the cosmos – using a low-frequency radio telescope in the Australian hinterland.
The pulsar was detected with the Murchison Widefield Array Telescope (MWA) in the remote Mid West region of Western Australia.
This is the first time scientists have discovered a pulsar with the MWA, but they believe it will be the first in a long series.
The discovery is a sign that things will come from the multibillion-dollar Square Kilometer Array (SKA) telescope. The MWA is a precursor telescope of the SKA.
Nick Swainston, a doctoral student at Curtin University’s node of the International Center for Radio Astronomy Research (ICRAR), made the discovery while processing data collected as part of an ongoing pulsar investigation.
“Pulsars are born as a result of supernovae – when a massive star explodes and dies, it can leave behind a collapsed nucleus known as a neutron star,” he said.
“They’re about one and a half times the mass of the Sun, but they’re all squeezed within 12 miles, and they have super-strong magnetic fields.”
Mr Swainston said the pulsars spin rapidly and emit electromagnetic radiation from their magnetic poles.
“Every time this show sweeps through our field of view, we see a pulse – that’s why we call them pulsars,” he said. “You can imagine it as a giant cosmic beacon.”
ICRAR-Curtin astronomer Dr Ramesh Bhat said the newly discovered pulsar is located more than 3,000 light years from Earth and rotates about once per second.
“It’s incredibly fast compared to regular stars and planets,” he said. “But in the world of pulsars, that’s pretty normal.”
Dr Bhat said the discovery was made using about one percent of the large volume of data collected for the pulsar investigation.
“We have only scratched the surface,” he said. “When we do this large-scale project, we should find hundreds of pulsars in the years to come.
Astronomers use pulsars for several applications, including testing the laws of physics under extreme conditions.
“A spoonful of material from a neutron star would weigh millions of tons,” Dr Bhat said.
“Their magnetic fields are among the strongest in the Universe – about 1,000 billion times more powerful than those we have on Earth.”
“So we can use them to do physics that we can’t do in any of the Earth-based labs.”
Finding pulsars and using them for extreme physics is also a key science engine for the SKA telescope.
MWA director Professor Steven Tingay said the find hints at a large population of pulsars awaiting discovery in the southern hemisphere.
“This discovery is really exciting because the data processing is incredibly difficult, and the results show the potential for us to discover many more pulsars with the MWA and the low frequency part of the SKA.
“Studying pulsars is one of the main areas of science for the multi-billion dollar SKA, so it’s great that our team is at the forefront of this work,” he said.