Something strange is out there in deep space, and astronomers using massive radio telescopes have found four mysterious objects that appear to be significantly circular at radio wavelengths and have a sort of brightness around them.
These objects aren't like any astronomical objects that have been seen in the past.
The Mysterious Deep Space Objects
The mysterious objects, which look like faraway islands shaped like rings, have been assigned odd radio circles, or ORCs for short. These objects were dubbed with that name since they are peculiar circular objects that are mysterious. The distance from us to these objects aren't known by astronomers yet, but they might be connected to galaxies far away.
The objects weren't located in the Milky Way galactic plane, and they are about one arcminute across, which pales in comparison to the moon's diameter of 31 arcminutes.
In the astronomers' paper that thoroughly goes over the discovery, there are a few possible explanations, but none of them match every one of the four ORCs. The main theory is that the objects are remnants of shockwaves that were left over after an extragalactic event, or it may be stray activity from a radio galaxy.
An astronomer at the Royal Military College of Canada and Queen's University, Kristine Spekkens, said that the objects might branch from a phenomenon that hasn't been probed before. Spekkens wasn't involved with the discovery or study at all, but she states that the objects are an extension of a class of objects that are already known to us.
Spekkens mentioned that the objects might be the result of some other phenomena. The ORCs are bright when viewed via radio wavelengths, but it's not visible when viewed in visible, infrared, and x-ray light.
Half of the ORCs are formed around galaxies that you can see in visible wavelengths. It suggests that the galaxies are what formed these mysterious objects. Two of the ORCs are close to each other, which might suggest that they have linked origins.
How Were These Objects Found?
The astronomers who found the objects discovered three of the objects while mapping the night sky using radio frequencies, which was a part of a pilot survey for the project EMU. EMU stands for the Evolutionary Map of the Universe. The EMU's pilot survey used the ASKAP, which stands for the Australian Square Kilometer Array Pathfinder, from July to November in 2019.
The ASKAP uses 36 dish antennas that work in tandem to watch the night sky with a wide-angle view. But this wasn't what found the fourth ORC.
The fourth ORC was found in archival data that was collected by India's Giant MetreWave Radio Telescope. The discovery helped the astronomers confirm that the ORCs were real and that it wasn't an issue with the telescope or the data analysis.
Only four ORCs have been discovered currently, and astronomers can't tell what the true nature of these mysterious objects are. The EMU survey has begun recently, which means that more unusual objects might show themselves.