Another example of an unusual huge structure was found in space – a strange radio circle. In fact, it is not a circle, but a sphere that surrounds some galaxies for reasons that are not yet fully clear. But the new finding provides some clues as to the possible nature of this phenomenon. Astronomers have been reporting strange radio circles (or ORCs for short) since 2019. Only a few have been found since then. For example, in December 2023, they mentioned six such objects. Since these structures can only be seen with radio telescopes, they probably emit only radio radiation.

Those found so far reach a million or even a million and a half million light years. We will remind you that the diameter of the disk of our Milky Way galaxy is approximately one hundred thousand light years. As it turns out, these spheres essentially surround galaxies. What’s interesting is the elliptical. They are, as a rule, larger than spirals and often arise as a result of galactic mergers.

Why radio circles appear is currently being investigated, but it is already understood that radio radiation is emitted by high-energy electrons and that this is the product of a type of shock wave of galactic proportions. It is only necessary to understand what caused such a “shock”.

Recently, a team of astronomers from Australia, Great Britain and South Africa reported a new discovery: Another ORC was located billions of light-years away. An article about him was published on the Cornell University preprint server. According to scientists, the diameter of this strange radio circle is only around 372 thousand light-years, which is several times smaller than any previously discovered.

As it turns out, there is an elliptical galaxy at the center of the object. It has some sort of extended structure and other features that suggest a recent merger with another galaxy. In addition, two companion galaxies are clearly visible, which speaks of gravitational interaction and caused by this disturbance. Therefore, regarding the new strange radio circle, astronomers suspect that the shock wave that caused it is one of the consequences of the meeting of galaxies.

As for the other sphere, astronomers previously concluded that it was the result of numerous simultaneous supernova explosions. When a galaxy “boils with life”, a large number of new massive stars are immediately formed in it. Such stars are very short-lived and only after 10-20 million years they all “exhaust” and turn into the newest ones. The star “baby boom” soon turns into general fireworks, and behind it, according to scientists, a strange radio circle remains as a “haze”.

And two more strange radio circles are notable in that they are directly adjacent to each other, resembling a kind of binary structure, and between them is an active galactic nucleus – a supermassive black hole at the center of a young, forming star. A galaxy that greedily absorbs the matter around it.