Astronomers wonder about a strange unusual object discovered in the Milky Way
Sylvie Claire / January 28, 2022
Australian astronomers have discovered a strange spinning object in the Milky Way that they say is unlike anything previously observed, according to a scientific paper published in the latest edition of the journal Nature.
The object, first spotted by a student working on his undergraduate thesis, produces significant electromagnetic radiation three times an hour. The waves are emitted every 18.18 minutes, explains astrophysicist Natasha Hurley-Walker, who observed the phenomenon through a giant low-frequency radio telescope in the Australian outback.
Although there are other objects in the universe that emit regular radio variations, such as pulsars, this frequency has never been observed before, she says. The discovery of this object was a little scary, she adds, because there is nothing known in the sky that does this.
The team determined that the object is about 4,000 light-years from Earth, incredibly bright and with an extremely strong magnetic field. But many mysteries remain to be unraveled. If you do all the calculations, you find that it shouldn't have enough power to produce these kinds of radio waves every 20 minutes. It just shouldn't be possible, Hurley-Walker said.
It could be a magnetar with an ultra-long period, a phenomenon theorized by researchers but never yet observed, or a white dwarf, an aging star with a surface temperature twice that of the sun. But it is also quite unusual, says the astrophysicist. We know of only one white dwarf pulsar, and nothing as large as this one. Of course, it could be something we never thought of. It could be an entirely new type of object, she says.
The research team was able to observe the signal over a wide range of frequencies. This means that it must be a natural process, it is not an artificial signal, the scientist assured when asked if this strong and coherent radio signal from space could have been sent by another life form.
The next step for researchers is to search the universe for more of these strange objects. More detections will tell astronomers whether this is a rare one-time event or a large new population that we've never noticed before, Hurley-Walker said.