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NRC’s adaptive optics help astronomers see better and farther into space – National Research Council Canada – Conseil national de recherches Canada

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Twinkling stars have enchanted humans since the dawn of time. But they make it hard for astronomers to get clear images of the skies. Great news: advanced technology developed by the National Research Council of Canada (NRC) takes the twinkle out, and changes the game for studying our universe.

Once the light from a star enters the earth’s atmosphere, it passes through several layers of air turbulence that appear to make the light flicker or twinkle. This effect also distorts images taken by telescopes on the ground. Fortunately, scientists can now remove that atmospheric disturbance with adaptive optics, clearing the air for those telescopes to take crisp, pure images.

Researchers at the NRC’s Herzberg Astronomy and Astrophysics Research Centre have developed an experimental adaptive optics system that is undergoing rigorous tests on their 1.2-metre McKellar Telescope in British Columbia. This project—Research, Experiment and Validation of Adaptive Optics with a Legacy Telescope (REVOLT)—uses advanced cameras, high-speed computers and bendable mirrors to correct the effects of atmospheric turbulence. With adaptive optics, the images produced by telescopes on earth can be as high-quality and high-resolution as they would be from telescopes in space above the atmosphere, and cost much less.

According to Dr. Jean-Pierre Véran, Adaptive Optics team leader at the Herzberg Astronomy and Astrophysics Research Centre, REVOLT has immense implications for larger optical telescopes now in place (up to 10 metres) and in development (up to 39 metres). “Time on these big telescopes around the world is in very high demand, so when they acquire new technology, they want proof that it has a very high level of maturity,” he says. “REVOLT serves as a test bench that allows us to validate new technologies on a small telescope in operational conditions.”

Image of the star Alpha Persei with the system off (left) and on (right) shows REVOLT improved the resolution by a factor of 5 and the sensitivity by a factor of almost 500.

He points out that the project, which took about 2 years to complete, was successfully tested on the McKellar Telescope for the first time in August 2022, with more observations planned for September. “This means we can see an object almost 500 times fainter with the same amount of observing time, which is an illustration of one of the key benefits of Adaptive Optics for large research telescopes,” says Dr. Kathryn Jackson, Adaptive Optics scientist at the Herzberg Astronomy and Astrophysics Research Centre. The research showed that REVOLT was able to efficiently correct the atmospheric turbulence, demonstrating that 2 novel technologies performed as expected when tested in operational conditions. These are the Herzberg Extensible Adaptive Real-Time Toolkit (HEART) and a new commercial high-speed camera called C-Blue One.

Real-time control platform and camera

HEART’s first client, the Gemini North Observatory in Hawaii, tasked the researchers to work with the Gemini North Adaptive Optics (GNAO) imager to fix the twinkle for the observatory’s massive telescope.

The instrument’s real-time controller (RTC) is based on HEART, created by the research centre’s multidisciplinary team. HEART’s layout, architecture and tools make it easy to adapt to and drive any adaptive optics system. The GNAO RTC acts as the brain of the system, which processes incoming natural and laser-guide star sensor signals and issues commands to the deformable mirrors.

“This system will be able to capture astronomical images with unprecedented resolution, sensitivity and contrast,” says Jennifer Dunn, head of the research centre’s Software Group. “Once installed, it will significantly increase the scientific productivity of Gemini.” HEART will also be deployed on several adaptive optics systems in observatories around the world.

An integral part of the platform is the new commercial C-Blue One camera by First Light Imaging. The REVOLT experiment was the first time this camera was used in an AO system on a telescope observing real astronomical objects. In REVOLT, this CMOS low-noise digital camera takes 1000 high-resolution images per second.

Putting it all together

The multidisciplinary REVOLT team includes engineers and scientists specializing in adaptive optics, software, high-precision opto-mechanics and electronics. They will also be working with other NRC research centres that will use the test bed starting this fall.

For example, the REVOLT system will be used to feed corrected starlight into an optical fibre, to enable an on-sky demonstration of a novel fibre-fed prototype instrument known as a spectral correlation sensor. This sensor, which was jointly developed by researchers at the Herzberg Astronomy and Astrophysics and Advanced Electronics and Photonics research centres, exploits the advantages of silicon photonics chip technology to produce an ultra-compact, lightweight astronomical instrument that will be used for high-sensitivity, real-time, remote gas detection in stellar and planetary atmospheres. This will be the first field test of this new instrument technology, using real operating conditions at a professional grade telescope.

Furthermore, the NRC’s Nanotechnology Research Centre will test-drive a new generation of low-voltage deformable mirrors (LVDM) on REVOLT. LVDM can correct distorted images from land-based telescopes and ground-to-space communications waves due to turbulence in the atmosphere. LVDM is key to integrate various components of a Micro-Electro-Mechanical System Deformable Mirror, including the mirror face sheet, the electromagnetic actuator, the circuits on a semiconductor wafer and the printed circuit board, all because of low driving voltage utilized by the electromagnetic force (known as the Lorentz force) from a powerful permanent magnet. LVDM is helping to compensate for atmospheric turbulence in real time with incredibly low power consumption, high mirror displacement, high fill factor of the reflective deformable mirror surface, and with a 1 millisecond response time.

REVOLT is instrumental in demonstrating novel technologies that are critical to the advancement of adaptive optics, which is key to progress in astronomy and physics, and in our understanding of how nature works. Adaptive optics also enables disruptive technologies used in many fields, including telecommunications, ophthalmology, microscopy and laser treatment of diseases.

“It has many long-term benefits for Canadians and other citizens of the world, and the faster we are able to develop these new technologies, the sooner we can effect important changes,” concludes Dr. Véran.

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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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