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Why astronomers are wondering whether Orion's shoulder will soon explode – CBC.ca

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The dramatic dimming of a giant star has astronomers wondering whether it’s getting ready to explode. 

Betelgeuse — the red shoulder on the left side in the constellation Orion — has dimmed by a factor of about two since October, a change that has never been documented before.

“We know that it’s the dimmest it’s been observed ever, based on the data we have,” said Stella Kafka, chief executive officer of the American Association of Variable Star Observers

What makes this development particularly intriguing to astronomers is that the star is slated to explode in spectacular fashion: a supernova. Astronomers estimate this will happen relatively soon — in astronomical terms anyway. It could be today, tomorrow or 100,000 years from now.

And when Betelgeuse goes supernova, astronomers estimate it will be as bright as the full moon and visible even during the day.

The tricky thing is that, because Betelgeuse is a red supergiant cloaked in a cloud of dust and gas, it’s difficult to accurately describe it.

It’s believed to be anywhere between 425 to 650 light years away, with a mass roughly 10 times that of the sun. It is also huge — likely 1,400 times larger than the sun. If it sat where the sun does, it would swallow all the inner planets, including Earth, Mars and even Jupiter. It’s also about 14,000 times more luminous than our comparatively small star.

But Betelgeuse is also a variable star, meaning its brightness rises and falls periodically. But we’ve never seen it like this.

“Maybe 300 years ago, Betelgeuse was dimmer than what we’re observing now, but we don’t have data,” Kafka said. 

This image, made with the European Southern Observatory’s Atacama Large Millimeter/submillimeter Array (ALMA) telescope, shows the red supergiant Betelgeuse — one of the largest known stars. If it were at the centre of our solar system, Betelgeuse would engulf Mercury, Venus, Earth, Mars and even Jupiter. (ALMA (ESO/NAOJ/NRAO)/E. O’Gorm)

 

So, does this dimming portend a potentially historic and magnificent explosion?

Maybe. Maybe not.

It’s not quite clear why exactly Betelgeuse dims periodically, but one of the possibilities is that, like the sun, it has cooler and hotter parts. If one of those cooler parts swung into our line of sight, that could make it seem like the star had dimmed.

In 2018, Betelgeuse had a couple of dips in its brightness, Kafka said. What we’re seeing now could be that same spot, or possibly another.

Plus, dimming isn’t necessarily indicative of an impending explosion.

There’s no telling what will happen next.

“I don’t even know if that’s the dimmest it’s going to get. This is an event that has been evolving,” Kafka said. “We’re still in the middle of it. Well, we’re still actually at the beginning of it. These kinds of massive stars move slowly. They take their sweet time.”

A history of supernovas

Astronomers spot supernovas somewhat regularly, though in other galaxies.

The last one in our galaxy that may have been observed from Earth was Cassiopeia A in 1680. 

Astronomers estimate that supernovas occur in galaxies like ours once every 100 years or so, though that doesn’t mean we will witness them all; they could be on the other side of the galaxy, for example, or hidden from view.

The supernova remnant Cassiopeia A as seen by the Chandra X-Ray Observatory. The blue dot in the centre of the image is identified as a young neutron star. (NASA/CXC/SAO; Optical: NASA/STScI; Infrared: NASA/JPL-Caltech/O. Krause)

A perfect example is a study published in 2008 that detected the remnant of a supernova in the Milky Way that was traced back roughly 140 years. It wasn’t visible to the naked eye, as it lay close to the centre of the galaxy and was obscured by dust and gas.

So we may be due for one soon.

No mutants

Kafka said there’s no need to panic: even if Betelgeuse were to explode, it wouldn’t obliterate life on Earth or turn us into mutants, though we would notice the blow of radiation it would deliver.

“What I will tell you is that it will be super interesting,” Kafka said.

“It will be an excellent opportunity to study a supernova in the making.”

The star could explode in two ways, she said. Either in two beams from its poles, or with a spherical, symmetrical explosion in all directions. If we were in the way of the beam-type explosion — which we’re not — or if Betelgeuse was a lot closer, we’d be in trouble.

But for now, you can carry on enjoying the holidays, if that’s what you were planning.

“We’re not going to die,” Kafka said. “But if you’re looking for an excuse to eat more this Christmas, go for it.”

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New species of crested dinosaur identified in Mexico

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A team of palaeontologists in Mexico have identified a new species of dinosaur after finding its 72 million-year-old fossilized remains almost a decade ago, Mexico’s National Institute of Anthropology and History (INAH) said on Thursday.

The new species, named Tlatolophus galorum, was identified as a crested dinosaur after 80% of its skull was recovered, allowing experts to compare it to other dinosaurs of that type, INAH said.

The investigation, which also included specialists from the National Autonomous University of Mexico, began in 2013 with the discovery of an articulated tail in the north-central Mexican state of Coahuila, where other discoveries have been made.

“Once we recovered the tail, we continued digging below where it was located. The surprise was that we began to find bones such as the femur, the scapula and other elements,” said Alejandro Ramírez, a scientist involved in the discovery.

Later, the scientists were able to collect, clean and analyze other bone fragments from the front part of the dinosaur’s body.

The palaeontologists had in their possession the crest of the dinosaur, which was 1.32 meters long, as well as other parts of the skull: lower and upper jaws, palate and even a part known as the neurocranium, where the brain was housed, INAH said.

The Mexican anthropology body also explained the meaning of the name – Tlatolophus galorum – for the new species of dinosaur.

Tlatolophus is a mixture of two words, putting together a term from the indigenous Mexican language of Nahuatl that means “word” with the Greek term meaning “crest”. Galorum refers to the people linked to the research, INAH said.

 

(Reporting by Abraham Gonzalez; Writing by Drazen Jorgic; Editing by Ana Nicolaci da Costa)

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Alberta family searches for answers in teen's sudden death after COVID exposure, negative tests – CBC.ca

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A southern Alberta mother and father are grappling with the sudden, unexplained death of their 17-year-old daughter, and with few answers, they’re left wondering if she could be the province’s youngest victim of COVID-19.

Sarah Strate — a healthy, active Grade 12 student at Magrath High School who loved singing, dancing and being outdoors — died on Monday, less than a week after being notified she’d been exposed to COVID-19.

While two tests came back negative, her parents say other signs point to the coronavirus, and they’re waiting for more answers. 

“It was so fast. It’s all still such a shock,” said Sarah’s mother, Kristine Strate. “She never even coughed. She had a sore throat and her ears were sore for a while, and [she had] swollen neck glands.”

Kristine said Sarah developed mild symptoms shortly after her older sister — who later tested positive for COVID-19 —  visited from Lethbridge, one of Alberta’s current hot spots for the virus.

The family went into isolation at their home in Magrath on Tuesday, April 20. They were swabbed the next day and the results were negative.

‘Everything went south, super-fast’

By Friday night, Sarah had developed fever and chills. On Saturday, she started vomiting and Kristine, a public health nurse, tried to keep her hydrated.

“She woke up feeling a bit more off on Monday morning,” Kristine said. “And everything went south, super-fast.”

Sarah had grown very weak and her parents decided to call 911 when she appeared to become delirious.

“She had her blanket on and I was talking to her and, in an instant, she was unresponsive,” said Kristine, who immediately started performing CPR on her daughter.

When paramedics arrived 20 minutes later, they were able to restore a heartbeat and rushed Sarah to hospital in Lethbridge, where she died.

“I thought there was hope once we got her heart rate back. I really did,” recalled Sarah’s father, Ron.

“He was praying for a miracle, and sometimes miracles don’t come,” said Kristine.

Strate’s parents say her health deteriorated quickly after being exposed to COVID-19. She died at Chinook Regional Hospital in Lethbridge on Monday. (Ron Strate)

Searching for answers

At the hospital, the family was told Sarah’s lungs were severely infected and that she may have ended up with blood clots in both her heart and lungs, a condition that can be a complication of COVID-19.

But a second test at the hospital came back negative for COVID-19.

“There really is no other answer,” Ron said. “When a healthy 17-year-old girl, who was sitting up in her bed and was able to talk, and within 10 minutes is unconscious on our floor — there was no reason [for it].”

The province currently has no record of any Albertans under the age of 20 who have died of COVID-19.

According to the Strate family, the medical examiner is running additional blood and tissue tests, in an effort to uncover the cause of Sarah’s death.

‘Unusual but not impossible’

University of Alberta infectious disease specialist Dr. Lynora Saxinger, who was not involved in Sarah’s treatment, says it is conceivable that further testing could uncover evidence of a COVID-19 infection, despite two negative test results.

However, she hasn’t seen a similar case in Alberta.

“It would be unusual but not impossible because no test is perfect. We have had cases where an initial test is negative and then if you keep on thinking it’s COVID and you re-test, you then can find COVID,” she said.

According to Saxinger, the rate of false negatives is believed to be very low. But it can happen if there are problems with the testing or specimen collection.

She says people are more likely to test positive after symptoms develop. 

“The best sensitivity of the test is around day four or five of having symptoms,” she said. “So you can miss things if you test very, very early. And with new development of symptoms, it’s always a good time to re-test because then the likelihood of getting a positive test is a little higher. But again, no test is perfect.” 

Sarah deteriorated so quickly — dying five days after she first developed symptoms — she didn’t live long enough to make it to her follow-up COVID-19 test. Instead, it was done at the hospital.

‘An amazing kid’

The Strate family now faces an agonizing wait for answers — one that will likely take months — about what caused Sarah’s death.

But Ron, who teaches at the school where Sarah attended Grade 12, wants his daughter to be remembered for the life she lived, not her death.

Strate, pictured here at three years old, had plans to become a massage therapist. She attended Grade 12 at Magrath High School and was an active, healthy teenager who was involved in sports, music and the school’s suicide prevention group. (Ron Strate)

Sarah was one of five children. Ron says she was strong, active and vibrant and had plans to become a massage therapist after graduating from high school.

She played several sports and loved to sing and dance as part of a show choir. She was a leader in the school’s suicide prevention group and would stand up for other students who were facing bullying.

“She’s one of the leaders in our Hope Squad … which goes out and helps kids to not be scared,” he father said.

“She’s an amazing kid.”

Sarah would often spend hours helping struggling classmates, and her parents hope her kindness is not forgotten.

“She’d done so many good things. Honestly, I’ve got so many messages from parents saying, ‘You have no idea how much your daughter helped our kid,'” said Ron.

“This 17-year-old girl probably lived more of a life in 17 years than most adults will live in their whole lives. She was so special. I love her so much.”

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China launches key module of space station planned for 2022

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BEIJING (Reuters) -China launched an unmanned module on Thursday containing what will become living quarters for three crew on a permanent space station that it plans to complete by the end of 2022, state media reported.

The module, named “Tianhe”, or “Harmony of the Heavens”, was launched on the Long March 5B, China’s largest carrier rocket, at 11:23 a.m. (0323 GMT) from the Wenchang Space Launch Centre on the southern island of Hainan.

Tianhe is one of three main components of what would be China’s first self-developed space station, rivalling the only other station in service – the International Space Station (ISS).

The ISS is backed by the United States, Russia, Europe, Japan and Canada. China was barred from participating by the United States.

“(Tianhe) is an important pilot project in the building of a powerful nation in both technology and in space,” state media quoted President Xi Jinping as saying in a congratulatory speech.

Tianhe forms the main living quarters for three crew members in the Chinese space station, which will have a life span of at least 10 years.

The Tianhe launch was the first of 11 missions needed to complete the space station, which will orbit Earth at an altitude of 340 to 450 km (211-280 miles).

In the later missions, China will launch the two other core modules, four manned spacecraft and four cargo spacecraft.

Work on the space station programme began a decade ago with the launch of a space lab Tiangong-1 in 2011, and later, Tiangong-2 in 2016.

Both helped China test the programme’s space rendezvous and docking capabilities.

China aims to become a major space power by 2030. It has ramped up its space programme with visits to the moon, the launch of an uncrewed probe to Mars and the construction of its own space station.

In contrast, the fate of the ageing ISS – in orbit for more than two decades – remains uncertain.

The project is set to expire in 2024, barring funding from its partners. Russia said this month that it would quit the project from 2025.

Russia is deepening ties with China in space as tensions with Washington rise.

Moscow has slammed the U.S.-led Artemis moon exploration programme and instead chosen to join Beijing in setting up a lunar research outpost in the coming years.

(Reporting by Ryan Woo and Liangping Gao; Editing by Christian Schmollinger, Simon Cameron-Moore and Lincoln Feast.)

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