Sure, we know that the universe is massive, endless, maybe. We know that what we know about it is only a very small part of it. A such infinitesimal part to can claim that we don’t know this universe. However the studiers thought to know it. Or at least they thought to know all the objects that are in it. As much as to can give a definition to every new object found, by placing it in one of the classifications already knew. But it isn’t true, there is still much to know out there. And the Odd Radio Circles (that’s the name of the new unknown objects) are something new, mysterious and weird of the universe.
The discovery of the Odd Radio Circles
To discover this new celestial body, completely different than the formations to which we are used, it was the team of researchers leaded by the astrophysicist Ray Norris, from the West Sydney University.
The ORCs (Odd Radio Circles) have been observed for the first time in the 2019, thanks to the radio observations of the EMU (Evolutionary Map of the Universe), that uses the Australian Square Kilometer Array Pathfinder, which is considered the most sensitive radio telescope in the world. This during the program Pilot Survey.
The ORCs, accidentally discovered, obviusly, because no one thought of their existence, “they don’t seem to match any king of unknown object”, say the researchers.
The Odd Radio Circles observed are four strange, odd, like the same name says, circle shaped objects. Th first one, in the middle, is matt, but the other three, around it, have bright edges.
Could it be an artefact?
“The big circled structures are known by the radio astronomers: usually they are circled objects produced by the residues of supernovas or planetary nebulas (which is what remains of a star explosion). Or even protoplanetary disks, that are solar systems being formed”, explains Norris.
But sometimes these unusual celestial formations are even artefacts, which take shape around lighting sources. This happens for some errors of calibration of the instruments.
Sometimes these errors are made by interferences. Sometimes even a simple microwave is able to create these artefacts!
But the scientists avoid all the hypothesis, by claiming that not, it isn’t a simple artefact, but a real new, unknown until now, object of the universe.
A discovery that comes from the past
After the incredible discovery the researchers wanted to do a jump in the past, to look for other proofs of the existence of the Odd Radio Circles. And they found them. The one of the 2019, infact, wasn’t the first time that a radiotelescope recorded an ORC.
In the archival datas of the radiotelescope Giant MetreWave they found out that in the 2013 was observed another object all alike the one discovered by the team of astrophysicists.
What do we know about the Odd Radio Circles?
We know that the ORCs discovered by Norris, the ones recorded in Australia in the 2019, occupy about the 3% of the space of sky occupied by a full moon. But they don’t know yet how far they are and this makes studying them very hard. They think anyway that they are outside the Milky Way, but this isn’t sure yet.
But what makes them very mysterious and odd is the fact that they are invisible to the X rays, to the infrared radiations and to the radiations of the visible. The only way to “see” them is a radio telescope.
In reality we can’t say nothing for sure about these mysterious celestial bodies, but the scientists are sure that they are something never saw before, and they start to assume their origin.
“We found an unaspected class of astronomical objects that don’t result previously reported on the Evolutive Map of the survey Pilot of the Universe, made by using the telescope Australian Square Kilometer Array Pathfinder.
These objects appear in the radio images as circled lightened disks and they don’t seem matching any kind of known object. We assume that they can represent a spherical shock wave caused by an extra galactical transitional event, or the outflow, or a residue, which comes from a radio view end-on galaxy.
Probably the objects aren’t the residue of a supernova, the structure that remains after the explosion of a star, but they might be the result of a spherical shock wave caused by the action of the galactical winds. We have to say though that, even if this is a theoretically possibility, these shock has never been observed somewhere else”.
This post is also available in: Italiano