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Discovery of record-breaking black hole collision surprises astronomers – CBC.ca

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A team of international astronomers has caught the merger of two black holes of unprecedented masses creating yet another massive black hole — one that astronomers believed existed in theory but that had never been detected.

The two caught in the act were roughly 85 times and 66 times the mass of the sun (measured as solar masses). After the pair merged — producing a gravitational wave picked up by detectors — they created a black hole 142 times the mass of the sun.

“We’ve never seen something like this before,” said Evan Goetz, a research associate at the University of British Columbia’s physics and astronomy department and co-author of the paper published on Wednesday in the journals Physical Review Letters and Astrophysical Journal Letters.

“This is the first time any type of gravitational signal like this has been measured.”

The discovery, called GW190521, was picked up using Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors in the United States and the Virgo interferometer in Italy on May 21, 2019. 

So far, gravitational waves — ripples in space-time caused by highly energetic processes in space, such as the merging of pairs of black holes or neutron stars or a black hole and a neutron star — typically create a sort of “chirp” noise on the detectors.

This artist’s drawing illustrates a hierarchical scheme for merging black holes. The LIGO and Virgo detectors recently observed a black hole merger with a final mass of 142 times that of the sun, making it the largest of its kind observed in gravitational waves to date. The event is thought to have occurred when two black holes of about 66 and 85 solar masses spiralled into each other and merged. (LIGO/Caltech/MIT/R. Hurt IPAC])

But this one, the researchers say, created more of a short-lived “bang,” producing only about five or six waveforms — which can be thought of as actual waves that oscillate. Comparatively, other gravitational-wave detections have produced hundreds of waveforms.

Due in part to its brief signal, astronomers had to ensure it wasn’t noise that was causing the suspected detection. Now that it has been confirmed, it is the first of its kind — and is shedding light on an elusive member of the black hole family: intermediate-mass black holes.

Surprises abound with discovery

There are two special parts to the findings: one, the sizes of the pair of black holes, particularly the one that is 85 solar masses; and two, the final black hole itself.

Black holes are regions in space where gravity is so strong that nothing can escape them. But they’re not all created equally.

According to theory, stars that are roughly 10 times the mass of the sun can die in a massive explosion — a supernova — that can produce a black hole. Stars that are roughly 65 times more massive are believed to destroy themselves. But stars that are more than 120 solar masses are believed to collapse directly into a black hole at the end of their lives.

So that means black holes between 65 and 120 solar masses shouldn’t even exist. Yet this new discovery contains two that fall within that range. The one that is 85 solar masses is particularly intriguing because it falls right in the middle.

WATCH | Simulation of binary black holes merging:

[embedded content]

Now to the final 142 solar-mass black hole.

There are stellar-mass black holes, which astronomers believe can go up to 10 to 100 times the mass of the sun. Then there are supermassive black holes, which can be found at the centre of most galaxies. These monsters can come in at millions or even billions of times the mass of the sun.

And while there have been theories about those black holes that are 100 solar masses or higher — called intermediate-mass black holes — none have been directly observed. 

Until now.

“There’s been no observational evidence prior to this discovery,” Goetz said. “This is the first conclusive evidence for an intermediate-mass black hole.”

Some hypotheses

There are two leading theories as to how these seemingly impossible things have come to be. One is that two stars could have merged to produce a black hole within the 65 to 85 range. The second is that multiple black holes could have merged within a dense star cluster, creating larger black holes of differing masses. 

“This is kind of exciting,” said Priya Natarajan, a theoretical astrophysicist and professor of astronomy and physics at Yale University in New Haven, Conn., whose main area of study is black holes. She was not involved with the research.

In a 2014 paper published in the journal Science, Natarajan and her colleague proposed that the creation of black holes similar to the 142 solar-mass one discovered last year could have come within a dense cluster of stars, much in the way the new discovery has been observed (though in her paper, the black hole was larger).

This chart compares the GW190521 merger event to others witnessed by LIGO and Virgo. The black hole created by the merger falls into a category known as an intermediate-mass black hole — and is the first clear detection of a black hole of this type. (LIGO/Caltech/MIT/R. Hurt [IPAC])

“The idea is one of the stars becomes a little black hole, and it starts wandering around and it’s kind of fed by the fire hose of gas [from stars]; it grows very fast,” Natarajan said. “And then it becomes massive, and it grows to about 50 times and then it sinks to the centre. 

“The second guy would roll around, but it wouldn’t grow as fast because there wouldn’t be as much gas left over. And so we predict that if you make two in that way, they cannot be the same mass, they will be different … and that’s what is seen now, so that’s kind of exciting.”

While the discovery is a first, the astronomers know that they need to increase their sample size to adequately explain the existence of intermediate-mass black holes.

“We need more observations of this type of signal. So, more mergers that yield intermediate-mass black holes will help us to understand … how they’re formed,” Goetz said. “Black holes play a key role in so many aspects of astrophysics that we’re only just now beginning to understand much more deeply with these observations.”

And more importantly, they will help us understand how we got here, as black holes are key to creating much of what exists.

“It’s part of the origin story of our universe,” Natarajan said. “We may not have been here if our Milky Way did not have black holes.”

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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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