Discovered a mysterious astronomical object that emits pulses every 18 minutes

Using the radio telescope Murchison Widefield Array (MWA) located in the Australian outback, researchers from Curtin University and the International Center for Research in Radio Astronomy (ICRAR) from that country have discovered an object unlike anything astronomers have seen before, as it sends out pulses of energy every nearly 20 minutes. It’s relatively close about 4000 light yearsin our own galaxy, as published this week in the magazine Nature.

“We found that the source emits pulses every 18.18 minutes, an unusual frequency which, to the best of our knowledge, has not been previously observed,” the authors note, “and when emission occurs, it is highly linearly polarized, bright, persists for 30 to 60 seconds at a time, and is visible over a wide range of frequencies.”

In principle, this unknown body could be a type of Neutron Star called Press, but they turn on and off in a matter of milliseconds or a few seconds, not every several minutes. Among them are the magnetarsendowed with a powerful magnetic field and spewing out huge amounts of high energy in the form of X-rays, gamma rays and sometimes also radio emissions.

One of the portions of the Murchison Widefield Array low-frequency radio telescope in Australia. /Pete Wheeler, ICRAR

During the observations, it was discovered that the mysterious object is smaller than the Sun and that, when rotating in space, it emitted beams of radiation – lasting up to one minute every twenty – that crossed the line of sight. At that time, she was one of the brightest radio sources from the sky. In addition, radio waves were emitted highly polarized, suggesting that it has an extremely strong magnetic field.

ultra long period magnetar

In their article, the researchers propose that this object could be an ultra-long period magnetar: “This is a type of slowly rotating neutron star whose existence has been theoretically predicted,” says the lead author, Natasha Hurley-Walker, “But nobody believed that we would directly detect one like this, because we didn’t expect them to be so bright; somehow it’s converting magnetic energy into radio waves far more efficiently than anything we’ve seen before.”

Ultra-long-period magnetars are a type of slow-spinning neutron star that had been predicted in theory, but no one believed we would detect one like this one, so bright.

Natasha Hurley-Walker (Curtin University/ICRAR)

Another possibility that the team is considering is that it is a strange white dwarf –collapsed nuclei that most stars turn into at the end of their lives– but with an ultra-strong magnetic field.

Hurley-Walker and his team continue to monitor the object with the MWA (Forerunner of the Future) radio telescope. Square Kilometer Array) to see if it turns on again. “If that happens, there are telescopes spread across the southern hemisphere and even in orbit that can point directly at it”, says the researcher, who intends to search for more unusual objects of this type in the vast archives of the MWA and with the help of the Pawsey Supercomputing Center. in Australia.

“Further detections will tell astronomers whether this is a single, rare event or a vast new population of objects that we haven’t detected before,” concludes Hurley-Walker.

Rights: Creative Commons.