Celebrity star Betelgeuse is smaller and closer to us than we knew

Betelgeuse. Betelgeuse. Betelgeuse.


ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella

If you’re experiencing the creepy sensation of someone breathing down your neck, then it might be Betelgeuse. The infamous star — the subject of an exciting will-it-or-won’t-it supernova discussion earlier this year — may actually be much closer to Earth than we suspected.

Betelgeuse is a red supergiant and it’s monstrous compared with the size of our sun. A study published in The Astrophysical Journal this week unveils some new calculations of the star’s mass and distance, and gives us an estimate for when it’s likely to go supernova. 

The speculation around Betelgeuse exploding kicked into high gear when the star went through some odd dimming and brightening episodes starting in late 2019. Scientists believe a dust cloud caused one of these events. “We found the second smaller event was likely due to the pulsations of the star,” said lead author Meridith Joyce, in a statement from The Australian National University (ANU) on Friday. 

The science team used modeling to sort out what was going with the pulsations, tracing it to what co-author Shing-Chi Leung of the University of Tokyo described as “pressure waves — essentially, sound waves.” This activity helped the researchers figure out where the star is in its life cycle.

Scientists had previously estimated this as the size of Betelgeuse compared with our solar system, but the new study revises that estimate down. 


ESO

The upshot is that Betelgeuse isn’t in danger of going supernova anytime soon. It could easily take 100,000 years before it gets to that stage. This is in line with what other scientists have suggested.

The study also shakes up our knowledge of the star’s size. “The actual physical size of Betelgeuse has been a bit of a mystery — earlier studies suggested it could be bigger than the orbit of Jupiter. Our results say Betelgeuse only extends out to two thirds of that, with a radius 750 times the radius of the sun,” said co-author Laszlo Molnar of the Konkoly Observatory in Budapest.

With Betelgeuse’s size dialed in better, the team was able to make a more accurate calculation of its distance from Earth, placing it at around 530 light-years away, or about 25% closer than previously known. That’s still plenty far enough that Earth won’t be harmed by Betelgeuse’s future explosion.

“It’s still a really big deal when a supernova goes off. And this is our closest candidate. It gives us a rare opportunity to study what happens to stars like this before they explode,” Joyce said.   

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Jonathan Davies: Wales centre knew of potential career risk after knee injury

Jonathan Davies on what he had to do to get back to playing rugby

Wales centre Jonathan Davies says he knew he was potentially risking his career by playing in the World Cup semi-final defeat against South Africa.

Davies played against the Springboks and New Zealand in the bronze medal match after damaging his knee against Fiji earlier in the tournament.

“I was told if I played the semi-final there was a risk of not finishing my career,” said Davies.

“It was worth the risk. I made that decision… it was something you do.”

Davies had missed the quarter-final win against France and his knee was heavily strapped for the final two matches of Wales’ 2019 campaign.

“It was tough going those last few games… I don’t think it was quite one leg, maybe one and a half!” said the 32-year-old Scarlet.

“I felt capable enough of going out there and giving a performance. It was heavily strapped and I was in pain but the hard work put in by the medical team to get me right to go out and play meant I was able to do that.”

Davies has since endured 11 months on the sidelines following an operation which he also knew could end his career.

“The uncertainty going into the surgery and not knowing what the outcome would be was the hardest thing to deal with,” said Davies.

“Once I knew at the 12-week mark the surgery was a success, it was a relief.

Jonathan Davies in action for Wales against New Zealand in the 2019 World Cup
Jonathan Davies in action for Wales against New Zealand in the 2019 World Cup

“The work I put in during those first 12 weeks to change my diet, that I looked after myself and didn’t do anything I shouldn’t was really important because there was a risk the injury could have ended my career.

“I made sure I did everything possible and thankfully we got a good result. I think that was down to a bit of luck, but a lot of it is also down to the work you put in away from rugby.”

Davies has played 81 times for Wales with two Grand Slams and three Six Nations titles to his name. He has also played six Tests on two British and Irish Lions tours, part of the series success in Australia in 2013 and being named man of the series in the drawn contest in New Zealand four years later.

So he was philosophical about being told his career might be on the line.

“It would have been tough and was tough hearing that, but I’ve been extremely fortunate,” said Davies.

“Rugby has been very kind to me and I’ve had some amazing experiences. Me being me and with the fortunate situation I’m in, I could have just about taken that. It was almost another challenge for me to then say, ‘this isn’t going to stop me. I am going to come back from this’.

“It did start a fire in me to keep pushing and striving to come

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