Modern Australian

newly discovered ghostly circles in the sky can't be explained by current theories, and astronomers are excited

  • Written by Ray Norris, Professor, School of Science, Western Sydney University

In September 2019, my colleague Anna Kapinska gave a presentation showing interesting objects she’d found while browsing our new radio astronomical data. She had started noticing very weird shapes she couldn’t fit easily to any known type of object.

Among them, labelled by Anna as WTF?, was a picture of a ghostly circle of radio emission, hanging out in space like a cosmic smoke-ring. None of us had ever seen anything like it before, and we had no idea what it was. A few days later, our colleague Emil Lenc found a second one, even more spooky than Anna’s.

newly discovered ghostly circles in the sky can't be explained by current theories, and astronomers are excited The ghostly ORC1 (blue/green fuzz), on a backdrop of the galaxies at optical wavelengths. There’s an orange galaxy at the centre of the ORC, but we don’t know whether it’s part of the ORC, or just a chance coincidence. Image by Bärbel Koribalski, based on ASKAP data, with the optical image from the [Dark Energy Survey](https://www.darkenergysurvey.org), Author provided

Anna and Emil had been examining the new images from our pilot observations for the Evolutionary Map of the Universe (EMU) project, made with CSIRO’s revolutionary new Australian Square Kilometre Array Pathfinder (ASKAP) telescope.

EMU plans to boldly probe parts of the Universe where no telescope has gone before. It can do so because ASKAP can survey large swathes of the sky very quickly, probing to a depth previously only reached in tiny areas of sky, and being especially sensitive to faint, diffuse objects like these.

I predicted a couple of years ago this exploration of the unknown would probably make unexpected discoveries, which I called WTFs. But none of us expected to discover something so unexpected, so quickly. Because of the enormous data volumes, I expected the discoveries would be made using machine learning. But these discoveries were made with good old-fashioned eyeballing.

Read more: Expect the unexpected from the big-data boom in radio astronomy

Hunting ORCs

Our team searched the rest of the data by eye, and we found a few more of the mysterious round blobs. We dubbed them ORCs, which stands for “odd radio circles”. But the big question, of course, is: “what are they?”

At first we suspected an imaging artefact, perhaps generated by a software error. But we soon confirmed they are real, using other radio telescopes. We still have no idea how big or far away they are. They could be objects in our galaxy, perhaps a few light-years across, or they could be far away in the Universe and maybe millions of light years across.

When we look in images taken with optical telescopes at the position of ORCs, we see nothing. The rings of radio emission are probably caused by clouds of electrons, but why don’t we see anything in visible wavelengths of light? We don’t know, but finding a puzzle like this is the dream of every astronomer.

Read more: The Australian Square Kilometre Array Pathfinder finally hits the big-data highway

We know what they’re not

We have ruled out several possibilities for what ORCs might be.

Could they be supernova remnants, the clouds of debris left behind when a star in our galaxy explodes? No. They are far from most of the stars in the Milky Way and there are too many of them.

Could they be the rings of radio emission sometimes seen in galaxies undergoing intense bursts of star formation? Again, no. We don’t see any underlying galaxy that would be hosting the star formation.

Could they be the giant lobes of radio emission we see in radio galaxies, caused by jets of electrons squirting out from the environs of a supermassive black hole? Not likely, because the ORCs are very distinctly circular, unlike the tangled clouds we see in radio galaxies.

Could they be Einstein rings, in which radio waves from a distant galaxy are being bent into a circle by the gravitational field of a cluster of galaxies? Still no. ORCs are too symmetrical, and we don’t see a cluster at their centre.

A genuine mystery

In our paper about ORCs, which is forthcoming in the Publications of the Astronomical Society of Australia, we run through all the possibilities and conclude these enigmatic blobs don’t look like anything we already know about.

So we need to explore things that might exist but haven’t yet been observed, such as a vast shockwave from some explosion in a distant galaxy. Such explosions may have something to do with fast radio bursts, or the neutron star and black hole collisions that generate gravitational waves.

Read more: How we closed in on the location of a fast radio burst in a galaxy far, far away

Or perhaps they are something else entirely. Two Russian scientists have even suggested ORCs might be the “throats” of wormholes in spacetime.

From the handful we’ve found so far, we estimate there are about 1,000 ORCs in the sky. My colleague Bärbel Koribalski notes the search is now on, with telescopes around the world, to find more ORCs and understand their cause.

It’s a tricky job, because ORCS are very faint and difficult to find. Our team is brainstorming all these ideas and more, hoping for the eureka moment when one of us, or perhaps someone else, suddenly has the flash of inspiration that solves the puzzle.

It’s an exciting time for us. Most astronomical research is aimed at refining our knowledge of the Universe, or testing theories. Very rarely do we get the challenge of stumbling across a new type of object which nobody has seen before, and trying to figure out what it is.

Is it a completely new phenomenon, or something we already know about but viewed in a weird way? And if it really is completely new, how does that change our understanding of the Universe? Watch this space!

Authors: Ray Norris, Professor, School of Science, Western Sydney University

Read more https://theconversation.com/wtf-newly-discovered-ghostly-circles-in-the-sky-cant-be-explained-by-current-theories-and-astronomers-are-excited-142812

NEWS

Everything You Need to Know about 5G Technology

Smartphone users today want faster data speeds, accompanied by more accessible services. 5G, the Next Generation of wireless networks claims to extend the same and much more. 5G allows users...

As Joe Biden prepares to become president, the US still reels from the deadly consequences of 'alternative facts'

Every four years on January 20, the US exercises a key tenant of democratic government: the peaceful transfer of power. This year, the scene looks a bit different.If the last...

Forget about the trade spat – coal is passé in much of China, and that's a bigger problem for Australia

Greg Baker/APAustralian coal exports to China plummeted last year. While this is due in part to recent trade tensions between Australia and China, our research suggests coal plant closures are...

Morrison government drops the ball on banking reform

Political pressure forced the federal government in 2017 – when Scott Morrison was treasurer – to call the royal commission into misconduct in the banking, superannuation and financial services sector.Commissioner...

The Rise and Fall of Saint George shows the transformative power of music

Bianca De Marchi/Sydney FestivalThe Rise and Fall of Saint George is a story about place, belonging and community that taps into universal tensions of identity and faith in multicultural societies...

why people can hold political views that disadvantage their own sex

The views of women and men can differ on important gendered issues such as abortion, gender equity and government spending priorities. Surprisingly, however, average differences in sex on this front...

is it safe for kids to go back to school? And what about the new mutant strain?

A year ago, in late January 2020, Australia reported its first cases of COVID-19. Since then, we have seen almost 29,000 confirmed cases and 909 deaths. As cases climbed in...

Not feeling motivated to tackle those sneaky COVID kilos? Try these 4 healthy eating tips instead

ShutterstockIn Australia and around the world, research is showing changes in body weight, cooking, eating and drinking patterns associated with COVID lockdowns.Some changes have been positive, such as people cooking...

The Conversation's submission to the Australian Senate Inquiry into the News Media Bargaining Code

BongkarnGraphic/ShutterstockOn 10 December 2020, the Australian Senate established an inquiry into a government bill proposing a ‘mandatory bargaining code’ between news media organisations and digital platforms including Google and Facebook...

Trumpism doesn't end with Trump — NZ needs to take a firmer stand against a global threat to democracy

America is currently experiencing its worst political and constitutional crisis since the civil war when the very survival of Abraham Lincoln’s government “of, by and for the people” was at...

older, underinsured and overexposed to cyclones, storms and disasters

News of storms battering parts of Queensland and the threat posed by Cyclone Kimi reminded me of a recent experience I’d had.A few months after Cyclone Marcus unleashed havoc on...

The economy can't guarantee a job. It can guarantee a liveable income for other work

When the coronavirus pandemic hit Australia in March 2020, the Morrison government took bold and imaginative action. The most notable examples were its income support programs – JobKeeper, paying a...



News Co Media Group

Content & Technology Connecting Global Audiences

More Information - Less Opinion













Popular articles from Modern Australian

Importance of Texture and Layering in Interior Design3 Ways Your Drains Become Blocked 5 Reasons for No Power at HomeHow Is Tequila Made?Why You Should Enlist The Services Of A Property StylistTop Luxury Resorts For A Restorative Staycation In AustraliaUnderstanding Employee Car Allowance Rates in Australia7 Bucket-List Worthy Experiences in DubaiThe Effects of Pollen Throughout the Year What Qualifications Are Required to Work as a Chef in Australia?How You Can Create A Café With A Shipping ContainerA Few Great Uses For Laundry DetergentHow To Make Living With Housemates SimplerGreat Tips For Buying Flowers For Valentine’s Day Mercedes-AMG GT Black Series Becomes The Fastest Sports Car