Astronomers at the University of Sydney have discovered a dead star 13,000 light-years away from Earth that spins incredibly slowly, taking 6.45 hours to complete a single rotation.
This discovery was made in January 2024 by a team led by Yu Wing Joshua Lee, an astronomer from the University of Sydney, studying data from the CSIRO’s ASKAP radio telescope in outback Western Australia.
The team was surprised to find this “slowpoke” star, officially named ASKAP J1839-075, as it takes thousands of times longer to spin than any other neutron star observed before.
Introducing Neutron Stars
Neutron stars are formed when massive stars collapse at the end of their lives. This collapse causes them to spin quickly, like a figure skater pulling their arms in for a faster spin. Imagine our Sun, which takes 27 days to rotate, suddenly spinning 1,000 times every second! That’s how fast these stars usually spin.
These stars are incredibly dense; imagine squeezing something with a radius of a million kilometres down to just 10 kilometres. They also emit radiation beams, and as they spin, these beams sweep past Earth like a lighthouse, which is why they are often called pulsars.
A Star that Breaks the Mould
Scientists previously thought that as pulsars lose energy and slow down, they would stop emitting these radiation beams and become invisible to our telescopes. However, ASKAP J1839-075 is challenging this idea. It’s spinning incredibly slowly but is still emitting radio waves, which has baffled astronomers. Mr. Lee said this discovery makes scientists rethink their theories about how these stars form and behave.
Australia’s Role in the Discovery
This isn’t the first time astronomers have found these slow-spinning stars. In recent years, other pulsars that take minutes or even up to an hour to rotate have been discovered. But ASKAP J1839-075, with its 6.45-hour rotation period, is in a league of its own.
According to Dr Gemma Anderson, an astronomer at Curtin University, Australia is leading the way in finding these unusual stars thanks to powerful radio telescopes like ASKAP and the Murchison Widefield Array.
Searching for Answers
While discovering these “slowpoke” stars is exciting, scientists still try to understand why they spin so slowly. Some believe they might be a special type of pulsar called a magnetar with a powerful magnetic field. Others suggest they could be a different type of star altogether.
More research is needed to solve this cosmic puzzle. Mr. Lee believes that many more of these stars may be waiting to be discovered, potentially opening up a whole new area of study in astronomy.
Published Date 22-Jan-2025