The enigmatic object, which releases a gigantic burst of energy three times an hour, is unlike anything astronomers have ever seen before.

Australian scientists have spotted a very unusual object in the night sky. It is a mysterious object that produced a massive burst of energy three times an hour in 2018. As the strange object spun through the universe, it emitted a beam of radiation that exactly crossed our line of sight. It was then one of the brightest radio sources in the sky for one minute.

transients

The object was discovered using the Murchison Widefield Array (MWA) telescope, located in the outback of Western Australia. And it seems that the object went ‘on’ and ‘off’ again just like a traffic light. Incidentally, such objects are not a rarity; astronomers call them “transients.” And these come in all shapes and sizes. For example, slow transients, such as supernovas, can appear over the course of a few days, then disappear after a few months. In addition, there are also fast transients, such as a neutron star, which flash for a few milliseconds to seconds.

peculiar

What makes the now discovered object so peculiar, however, is that it gave an appearance for one minute at a time. “This object appeared and disappeared for a few hours during our observations,” said study leader Natasha Hurley-Walker. “That was totally unexpected. It was even a little creepy, because nothing in the night sky is known to do the same.” In addition, the mysterious object is quite close to us, only 4,000 light-years away. “It’s in our own galactic backyard,” said Hurley-Walker.

What could it be?

The researchers have been puzzling over what the mysterious object might be. What we know is that the spinning object is incredibly bright and slightly smaller than our sun. In addition, it emits highly polarized radio waves. This means that it has an extremely strong magnetic field.

unique magnetar

It leads to an exciting theory. The researchers suspect that the enigmatic object may be a unique magnetar. Magnetars are incredibly magnetic neutron stars, some of which sometimes produce radio emissions. Known magnetars rotate every few seconds, but theoretically they could also rotate much slower. “The observations are consistent with such a predicted astrophysical object,” said Hurley-Walker. “It’s a kind of slow-spinning neutron star that’s theoretically predicted to exist. However, no one thought it would be directly observable. Somehow it converts magnetic energy into radio waves much more effectively than anything we’ve seen before.”

An artistic impression of what the object might look like if it were a magnetar. Image: ICRAR

The researchers plan to keep a close eye on the night sky using the MWA telescope. Although the puzzling object has not been seen for a while, it may just make itself heard again. “If so, we can point more telescopes at it,” Hurley-Walker says.

In addition, the researcher plans to dig through previously collected data from the MWA telescope to uncover more similar unusual objects. “This could tell us whether this was a rare, one-off event or whether it’s a massive new population that we haven’t noticed before,” concludes Hurley-Walker.