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| A newly discovered pulsar type emits intermittent radio bursts, distinct from continuously emitting pulsars. (Image: Nature) |
Astronomers have accidentally discovered a strange type of star that emits intermittent bursts of radio waves. While they resemble pulsars in their radio emission, they do so randomly rather than periodically like traditional pulsars.
“Discovering such a new type of object is quite unusual“, said Andrew Lyne, an astronomer at the Jodrell Bank Observatory, University of Manchester, UK. “It opens up a new field in astronomy“, he added.
The peculiar star was detected by the Parks radio telescope in New South Wales, Australia. To date, only 11 similar objects have been observed, referred to as Rotating Radio Transients (RRATs). These stars emit radio bursts every random interval ranging from 4 minutes to 3 hours, with each burst lasting between 2 to 30 seconds.
The bursts make them appear similar to pulsars—rapidly spinning neutron stars that consistently release a beam of radio waves, akin to a lighthouse. Each time this beam sweeps past Earth, our radio telescopes detect a click.
However, no one has ever observed a pulsar-like object that emits bursts at such irregular intervals as RRATs.
The research team encountered RRATs while searching for pulsars. “There are 11 regions in the sky where we occasionally see these flashes“, Lyne recalled. “It’s hard to believe that these flashes come from the universe, as they look very much like artificial noise“.
The team later realized that although the timing of the flashes varied significantly, they were always multiples of smaller time units, between 0.4 and 7 seconds, depending on the source.
Scientists concluded that RRATs may represent a previously unknown type of neutron star, spinning periodically (like a pulsar) but only occasionally emitting a radio pulse. When asked about the reason for this irregularity, Lyne admitted there is currently no evidence to explain it.
Vicky Kaspi, an astrophysicist at McGill University in Montreal, Canada, pointed out that some pulsars have been known to emit irregular secondary pulses in the past, although the astronomical community has struggled to explain this phenomenon.
“It’s possible that RRATs are doing the same thing“, Vicky Kaspi speculated, “except their periodic radio emissions are too faint for us to detect“.
T. An
