Western Sydney University researchers and an international team of experts have recently discovered a mysterious circular ring dubbed J0624–6948 between the Galactic Plane and the large Magellanic Cloud (LMC). This mysterious circular ring is also known as a “rogue” supernova remnant.
J0624–6948 was first detected with the Australian Square Kilometre Array Pathfinder (ASKAP). It may be the first known case of a space supernova remnant – the remains of an exploded star that could be up to 7000 years old.
When the team discovered this circular radio object, they initially thought that the object must be ORC (odd radio circle). Although, additional observations make it clear that the object is something else. Unlike other known ORCs, the J0624–6948 has significant differences:
- A flatter radio spectral index
- Lack of a prominent central galaxy as a possible host
- Larger apparent size
These distinct features suggest that the ring may be a different type of object.
Lead author Professor Miroslav Filipovic from the University’s School of Science said the discovery was exciting and raised many unanswered questions said: “The most plausible explanation is that the object is an intergalactic supernova remnant due to an exploded star that resided in the Large Magellanic Cloud outskirts that had undergone a single-degenerate type Ia supernova which involves the explosion of two stars orbiting each other.”
“However, we considered other scenarios such as that this object might represent a remnant of the super-flare activity from a nearby Milky Way star (at only 190 light-years away from the sun) that happened only a few centuries ago, or the premise that it may be a much larger ORC.”
“What we’ve potentially then discovered is a unique remnant of a supernova that has expanded into a rarefied, intergalactic environment—an environment that we didn’t expect to find in such an object. Our estimates point to the age of about 2,200 to 7,100 years old.”
“The discovery was exciting and raised many unanswered questions.”
- Miroslav D Filipović et al. Mysterious, odd radio circle near the large Magellanic cloud – an intergalactic supernova remnant? DOI: 10.1093/mnras/stac210