What the hell is this new thing in the Milky Way?

Astrophysicists are trying to identify this “really weird,” spinning, flickering maybe-star in the galaxy.

Credit: Dr. Natasha Hurley-Walker (ICRAR/Curtin)

Whenever I’m in the mood for an existential crisis, I like to look at news about space. Being able to remove my thoughts from this planet from a bit is always refreshing. Because while the early 2020s may be a wash for planet Earth, the universe keeps on doing its thing outside of us. I don’t know if there’s any better illustration of that than the news this week that Australian scientists have discovered an unknown space object in the Milky Way.

In 2018, Curtin University graduate student Tyrone O’Doherty discovered an object in the sky while using his own technique and the Murchison Widefield Array telescope in the Western Australia outback. He was part of a team from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR).

The object that O’Doherty found was releasing radiation three times per hour. Per CNN, it was the brightest source of radio waves viewable from Earth at the time and, essentially, a sort of “celestial lighthouse.”

“This object was appearing and disappearing over a few hours during our observations,” astrophysicist Dr. Natasha Hurley-Walker, who led the team that made the discovery, said in a press release. “That was completely unexpected. It was kind of spooky for an astronomer because there’s nothing known in the sky that does that.”

Hurley-Walker added, “And it’s really quite close to us — about 4000 lightyears away. It’s in our galactic backyard.”

Alright, so what the hell is this thing?

ICRAR’s team was able to establish that the object is really bright and smaller than the sun. Because its radio waves are highly-polarized, that suggests the object has an extremely strong magnetic field.

Working off that information, researchers are passing around theories that the object may be a neuron star or a white dwarf, which are the remains of a massive star’s death. Now, generally speaking, finding objects like this isn’t all that uncommon. In fact, objects in the sky that turn on and off have their own name: “transients.”

“When studying transients, you’re watching the death of a massive star or the activity of the remnants it leaves behind,” astrophysicist Dr. Gemma Anderson, who coauthored a report in Nature on the object, said in an ICRAR press release. “‘Slow transients’ — like supernovae — might appear over the course of a few days and disappear after a few months. ‘Fast transients’ — like a type of neutron star called a pulsar — flash on and off within milliseconds or seconds."

What made this new object “really weird,” Anderson said, was that it stayed on for about a minute every 18 minutes. Keeping that in mind, Hurley-Walker proposed that the object may be an ultra-long period magnetar, or, “a type of slowly spinning neutron star that has been predicted to exist theoretically.”

Currently, researchers are monitoring the object to see if it comes back on. Regardless of what the object is, for O’Doherty, “It’s exciting that the source I identified last year has turned out to be such a peculiar object.”