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Extremely rare 'cosmic ring of fire' discovered in the early universe – CNET

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The ring galaxy R5519 may have been created during a massive, catastrophic collision between two galaxies in the early universe.


James Josephides/Swinburne Astronomy Productions

A violent, catastrophic collision between two galaxies has given rise to an extremely rare ring galaxy, lurking some 11 billion light years from the Earth. The monstrous, donut-shaped galaxy is making stars in its huge ring at a rate 50 times faster than our home galaxy, earning it an ominous moniker Johnny and June Cash would surely dig: The cosmic “ring of fire.”

In a paper, published in the journal Nature Astronomy on Tuesday, an international team of scientists detail the ring galaxy R5519, discovered after scouring data from the Hubble Space telescope and the W.M. Keck observatory in Hawaii. Among almost 4,000 galaxies detected in the data sets, R5519 was one of the brightest and displayed a clear ring structure. So the team investigated further — and quickly realized they’d found something unusual. 

“It is very a curious object, one that we have never seen before,” says Tiantian Yuan, an astronomer at Swinburne University in Australia and first author on the study. “The gigantic hole in this galaxy was caused by a head-on collision with another galaxy.”  

Probing the features of R5519, Yuan and her team began picking up clues as to how it formed. They ruled out gravitational lensing or a galaxy merger for its unusual structure and nearby, they detected a companion galaxy — G5593. They suspect this cosmic neighbor is the “intruder” galaxy that may have collided with R5519 around 40 million years ago. 

The two galaxies must have smashed into each other pretty much head-on — a galactic bulls-eye — and it’s likely there was already a disk of stars present in R5519. As G5593 came swooping through the galaxy, it split the disk through the guts and a wave of stars expanded from the center, as seen in the GIF above.

“The collisional formation of ring galaxies requires a thin disk to be present in the ‘victim’ galaxy before the collision occurs,” said Kenneth Freeman, an astronomer at Australian National University and co-author on the paper, in a statement. 

If R5519 is caused by a huge collision, that would make it an extremely rare cosmic phenomena. Only one in every 10, 000 galaxies in the local universe are formed in such a way. Notably, the early universe was much more crowded so the belief was these kind of collisions may have been more common. Yuan suggests the data is telling a different story.

“Previously, people think we would find more of these collisional ring galaxies in the young universe, simply because there are more collisions back then,” she says. “We find that is not the case.”

There are still some “unsolved puzzles” about the ring of fire, Yuan says. “We do not know if this ring was a first ring after the collision or it was the second ring.” She’s obtained further data from W.M. Keck to resolve this issue.

Astronomers will have to gather more data to be certain the ring is caused by a collision, rather than through natural evolution. The authors of the paper write the imaging performed by NASA’s soon-to-be-launched (and recently-assembled) James Webb Space Telescope will be able to resolve any lingering questions. Yuan says she has already discovered another ring galaxy likely formed by a head-on collision — and this is a billion years older than the “ring of fire.”

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Rare comet passing over Manitoba sky | CTV News – CTV News Winnipeg

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WINNIPEG —
Stargazers in Manitoba can get a glimpse of the brightest comet in years as it hurtles past Earth over the next several days.

Comet NEOWISE C/2020 F3, named after the satellite that first discovered it, has been travelling towards Earth in recent days, before it returns to the outer edges of the solar system.

Photos submitted from Manitobans show the comet as it appeared in the morning sky on Thursday.

(Comet NEOWISE C/2020 F3 is pictured over Winnipeg in a pair of photos take July 9, 2020. Source: Roy Jemison)

comet neowise

(Comet NEOWISE C/2020 F3 is visible over Steinbach on July 9, 2020. SOURCE: Christopher Bleasdale)

Scott Young, who is the manager of the Planetarium and Science Gallery at the Manitoba Museum, said this comet wasn’t expected to be as bright as it is.

“This wasn’t predicted to be all that impressive but as it swung around the soon it suddenly burst into brightness,” said Young.

It’s one of the few “naked-eye comets” of the 21st century, meaning it can be seen without a telescope. The comet was first discovered on March 27, 2020, and NASA was unsure if it would make it to Earth as the comet travelled towards the sun.

Young said over the next several days this will be the only time to see the comet.

“We won’t see it again for at least 6,000 years. So it’s kind of your only chance.”

comet

(SOURCE: Scott Young/Manitoba Museum)

Young added the reason why this comet is so unique is because of how bright it is.

“I can count on the fingers of one hand how many comets we’ve had that have been this impressive. I mean, I have seen a lot of comets, but there’s only a couple that have outshone this in my entire lifetime.”

NASA said the comet will likely be visible in the early morning sky until July 11. It will be visible in the early evening sky after July 11.

Young says if people want to see it, it’s best to be away from the city and all the lights.

comet

(SOURCE: Scott Young/Manitoba Museum)

– With files from CTV’s Jackie Dunham.

Correction:

This is a corrected story. The original story said the comet was discovered in 2009, when it was discovered this year.

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Scientists Discover Unexplained Glowing Circles of Energy in Space – VICE

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​The Tycho supernova. Image: NASA/CXC/RIKEN & GSFC/T. Sato et al; Optical: DSS

The Tycho supernova. Image: NASA/CXC/RIKEN & GSFC/T. Sato et al; Optical: DSS 

Astronomers have discovered a bunch of weird unidentified circles in space, visible only in radio light, thanks to images captured by one of the most sensitive observatories on the planet.

The mysterious rings “do not seem to correspond to any known type of object” and so have been simply dubbed Odd Radio Circles, or ORCs, according to a new study, led by Western Sydney University astrophysicist Ray Norris.

“We have discovered, to the best of our knowledge, a new class of radio-astronomical object, consisting of a circular disc, which in some cases is limb-brightened, and sometimes contains a galaxy at its centre,” Norris and his colleagues said in the study, which was recently posted on the preprint server arXiv and has not yet been peer-reviewed.

“None of the known types of radio object seems able to explain it,” the team said.

The team describes four of these inscrutable ORCs, three of which were detected by the Australian Square Kilometre Array Pathfinder (ASKAP) telescope, a network of radio antennae that covers four square kilometers of the Australian Mid West. ASKAP has been scanning the sky in the radio spectrum to create an Evolutionary Map of the Universe that could help scientists better understand the development of stars and galaxies.

Norris and his colleagues noticed three odd blobs in ASKAP’s 2019 observations. Each of the circles measures about one arcminute across, which is roughly equivalent to 3 percent the diameter of the Moon. However, it’s difficult to tell how far away the ORCs are based on these images, and that in turn makes it challenging to estimate the actual size of the objects, at least until more detailed observations are made.

The glowing circles are so bizarre that Norris and his colleagues wondered if they might be an instrumental glitch, especially since radio imagery often contains errors that look like rounded apparitions, according to the study.

But when the team went hunting through archival datasets, they were surprised to discover that a fourth ORC was imaged all the way back in 2013 by India’s Giant Metrewave Radio Telescope, though nobody had made note of it at the time.

By combing through past radio surveys, as well as obtaining new images with the Australia Telescope Compact Array, the researchers were able to collect at least two independent observations of each ORC. The fact that the circles show up across multiple telescope datasets makes instrumental error “a very improbable explanation,” the team said in the study.

So if the ORCs are real celestial objects, what could they be? Norris and his colleagues outline several possible identities for the objects, though none of them are an obvious fit.

The circles might be the fallout of exploded stars, or bubbles blown out by winds in galactic star factories, or “Einstein rings,” which are signatures of warped spacetime created by the gravity of massive objects. They could be the ghosts of highly energetic events that occurred millions of years ago, such as gamma ray bursts, fast radio bursts, or plasma jets emitted by active galactic cores.

“We also acknowledge the possibility that the ORCs may represent more than one phenomenon,” the team noted, adding that they may have been “discovered simultaneously because they match the spatial frequency characteristics of the ASKAP observations, which occupy a part of the observational parameter space which has hitherto been poorly studied.”

Norris and his colleagues plan to continue examining the ORCS to see if they can tease out some of these tantalizing mysteries. One thing’s clear, however: discoveries like this are likely to become more common as radio astronomy matures in the coming years.

Within the next decade or so, ASKAP will join the Square Kilometre Array, a massive intercontinental observatory currently in construction, which will be by far the most sensitive radio instrument on Earth once it’s operational. The discovery of the ORCs is fascinating by itself, but it also foreshadows a new era of astronomy that is already sharpening our view of space.

This article originally appeared on VICE US.

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CINDY DAY: Don’t miss this once in a lifetime event to see Comet NEOWISE – SaltWire Network

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If you’ve been paying attention to the news lately, you are most likely familiar with the word “NEOWISE.” If not, let me introduce you:

NEOWISE is the name of a comet that was discovered in March 2020. This comet is visiting from the most distant parts of our solar system and for the next couple of weeks, could put on quite a show. The comet made its once-in-a-lifetime close approach to the Sun on July 3 and will cross outside Earth’s orbit on its way back to the outer parts of the solar system by mid-August.

On July 22, the comet will reach its closest point to Earth — a distance of 103 million kilometres — but because comets can be unpredictable, a little like the weather, experts are not sure that it will still be visible to the naked eye.

For the last few days, NEOWISE has been visible an hour before sunrise, very low in the northeastern sky. As of Sunday, the comet will be visible in the evening as well. About an hour after sunset, it will appear near the northwestern horizon. As the month goes on, it will rise higher in the sky, moving toward the Big Dipper. Right now, the comet is visible to the naked eye, but a good pair of binoculars would offer a better view. In very dark skies, you should be able to spot a nucleus and get a pretty good look at the fuzzy comet and its long, streaky tail.

Its name, in fact, is an acronym. The comet was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer or NEOWISE.

From its infrared signature, experts have discovered that the icy visitor is about five kilometres in diameter. It has a nucleus that is covered with sooty, dark particles left over from its formation near the birth of our solar system about 4.6 billion years ago.

After this encounter, astronomers expect Comet NEOWISE to bid farewell for quite some time. Its long, looping orbit around our star will bring it back to Earth’s vicinity more than 6,000 years from now.



Cindy Day is the chief meteorologist for SaltWire Network

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