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Astronomers trace mysterious fast radio burst to extreme, rare star – The Union Journal

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Sifting through a trove of radio telescope data in 2007, Duncan Lorimer, an astrophysicist at West Virginia University, spotted something unusual. Data obtained six years earlier showed a brief, energetic burst, lasting no more than 5 milliseconds. Others had seen the blip and looked past it, but Lorimer and his team calculated that it was an entirely new phenomenon: a signal emanating from somewhere far outside the Milky Way.

The team had no idea what had caused it but they published their results in Science. The mysterious signal became known as a “fast radio burst,” or FRB. In the 13 years since Lorimer’s discovery, dozens of FRBs have been discovered outside of the Milky Way — some repeating and others ephemeral, single chirps. Astrophysicists have been able to pinpoint their home galaxies, but they’ve struggled to identify the cosmic culprit, putting forth all sorts of theories, from exotic physics to alien civilizations

On Wednesday, a trio of studies in the journal Nature describes the source of the first FRB discovered within the Milky Way, revealing the mechanism behind at least some of the highly energetic radio blasts.

The newly described burst, dubbed FRB 200428, was discovered and located after it pinged radio antennas in the US and Canada on April 28, 2020. A hurried hunt followed, with teams of researchers around the globe focused on studying the FRB across the electromagnetic spectrum. It was quickly determined that FRB 200428 is the most energetic radio pulse ever detected in our home galaxy. 

In the suite of new papers, astrophysicists outline their detective work and breakthrough observations from a handful of ground- and space-based telescopes. Linking together concordant observations, researchers pin FRB 200428 on one of the most unusual wonders of the cosmos: a magnetar, the hypermagnetic remains of a dead supergiant star. 

It’s the first time astrophysicists have been able to finger a culprit in the intergalactic whodunit — but this is just the beginning. “There really is a lot more to be learned going forward,” says Amanda Weltman, an astrophysicist at the University of Cape Town and author of a Nature news article accompanying the discovery. 

“This is just the first exciting step.”

Under pressure

To understand where FRB 200428 begins, you have to understand where a star ends.

Stars many times larger than the sun are known to experience a messy death. After they’ve exhausted all their fuel, physics conspires against them; their immense size places unfathomable pressure on their core. Gravity forces the star to fold in on itself, causing an implosion that releases huge amounts of energy in an event known as a supernova. 

The star’s crumpled core, born under extreme pressure, is left behind. Except now it’s very small, only about the size of a city, and around 1 million times more dense than the Earth. This stellar zombie is known as a neutron star. 

Some neutron stars have extreme magnetic fields, about 1,000 times stronger than typical neutron stars. They’re a mysterious and intriguing class unto themselves. Astronomers call them “magnetars,” and they’re as curious as FRBs, with only about 30 discovered so far. 

See also: These telescopes work with your phone to show exactly what’s in the sky

One such magnetar in the Milky Way is officially known as SGR 1935+2154, which refers to its position in the sky. To make things easier, let’s nickname it Mag-1. It was first discovered in 2014 and is located around 30,000 light-years from Earth. On April 27, 2020, NASA’s Neil Gehrels Swift Observatory and Fermi Gamma-ray Space Telescope picked up a spike in X-rays and gamma-rays emanating from Mag-1. 

The next day, two huge North American telescopes — the Canadian Hydrogen Intensity Mapping Experiment (CHIME) and the Survey for Transient Astronomical Radio Emission 2 (STARE2) — picked up an extremely energetic radio burst coming from the same region of space: FRB 200428. The FRB and Mag-1 were in the exact same galactic neighborhood. Or rather, they seemed to be in the same galactic house. 

“These observations point to magnetars as a smoking gun of an FRB,” says Lorimer, lead author on the 2007 discovery of the first radio burst. Magnetars had been theorized as potential FRB sources previously, but the data provides direct evidence linking the two cosmic phenomena together.

However, just co-locating the burst with the magnetar doesn’t explain everything.

“Magnetars occasionally produce bursts of bright X-ray emission,” says Adam Deller, an astrophysicist at Swinburne University in Melbourne, Australia, “but most magnetars have never been seen to emit any radio emission.”

Don’t stop me now

Associating Mag-1 with FRB 200428 is just the beginning of a long-term investigation. 

In the cosmic whodunit, astronomers have found a culprit, but they’re not exactly sure of the murder weapon. 

Studying the FRB, researchers were able to determine it was highly energetic but paled in comparison to some deep space FRBs previously discovered. “It was almost as luminous as the weakest FRBs we’ve detected,” says Marcus Lower, an astronomy Ph.D. at Swinburne University studying neutron stars. This suggests magnetars may be responsible for some FRBs but not all of them — some seem far too energetic to be produced in the same way FRB 200428 was.

Another paper in Nature on Wednesday sees researchers using China’s Five-hundred-meter Aperture Spherical radio Telescope (FAST) to study Mag-1 during one of its X-ray outbursts. The telescope did not pick up any radio emission from the magnetar during its outbursts. That means it’s unlikely such an outburst, alone, is responsible for spewing highly energetic FRBs. “It’s definite that not every magnetar X-ray burst fires off an accompanying radio burst,” says Deller. 

Deller also notes that FRB 200428 shows characteristics similar to those seen in repeating FRBs from outside the Milky Way.

This is important because, at present, astronomers have observed two types of FRBs in other galaxies. There are those that  flash to life and disappear, and others that appear to be repeating with regular rhythm. FRB 200428 looks like a repeater, but much weaker. Further observations by the CHIME telescope in October detected more radio bursts from the magnetar, though this work hasn’t yet been published.

All in all, there’s still some uncertainty. “We cannot say for certain if magnetars are the sources of all of the FRBs observed to date,” Weltman notes. 

Another question: How did Mag-1 generate the FRB? Two different mechanisms have been proposed. 

One suggestion is magnetars produce radio waves just as they do X-rays and gamma-rays in their magnetosphere, the huge region of extreme magnetic fields surrounding the star. The other is a little more complex. “The magnetar could live in a cloud of material hanging around from previous outflows,” says Adelle Goodwin, an astrophysicist at Curtin University who was not affiliated with the study. This cloud of material, Goodwin notes, could then be slammed into by an X-ray or gamma-ray outburst, transferring energy into radio waves. Those waves then travel through the cosmos and ping Earth’s detectors as an FRB. 

It’s not clear which mechanism resulted in FRB 200428 — or if something more exotic might be happening. Other researchers have suggested FRBs may even be caused by asteroids slamming into a magnetar, for instance. But one thing now seems certain: it’s not alien civilizations trying to contact us. Sorry.

Radio ga-ga

There’s still a great deal of work to be done in unraveling the mystery of fast radio bursts. 

For Deller, the hunt continues. Part of his work is focused on where FRBs originate. He says his team still needs to collect more data, but there’s a chance that repeating FRBs may inhabit different types of galaxies from those FRBs which don’t repeat. Weltman notes the search for other signals will also intensify, with astronomers looking for electromagnetic radiation and neutrinos that are generated from any magnetar-produced FRB. 

The investigation will, ultimately, change the way we see the universe. Duncan Lorimer notes that if FRBs can be definitively linked to neutron stars, it would provide a way to take a census of those extreme cosmic entities. Current methods can’t identify neutron star types with great specificity — but FRBs could change that. And FRBs are already changing the way we see things. A study published in Nature earlier this year used FRBs to solve a decades-old problem about the universe’s “missing matter.” 

Lorimer says many of the predictions his team made after discovering the first FRB in 2007 “have been realized in some way” and he always hoped FRBs could become part of the mainstream. As the mysteries deepen, they’ve surpassed his expectations. They’ve become one of astrophysics’ most perplexing but intriguing phenomena. 

“It continues to be a fascinating adventure,” he says.

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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