Scientists conclude supergiant star Betelgeuse is smaller and closer than they thought. That’s according to astronomers from the Australian National University.
A study published in The Astrophysical Journal this week unveils some new calculations of the star’s mass and distance and shows us an estimate for when it’s likely to go supernova.
Since this website is free of ads, please consider supporting us on Patreon.
Betelgeuse is one of the brightest stars in the sky. In late 2019, it appeared to be dimming, thus, raising concerns that the star will explode soon.
But new research led by Dr. Meridith Joyce from the Australian National University (ANU) suggests that the dimming events were actually due to a dust cloud obscuring the star from Earth and the star’s natural pulsations.
You Might Like This: Mysterious Dimming of Betelgeuse Explained
The researchers have discovered that it may be another 100,000 years until the giant red star Betelgeuse dies in a fiery explosion. Their data also shows the star is both smaller and closer to Earth than previously thought.
“It’s normally one of the brightest stars in the sky, but we’ve observed two drops in the brightness of Betelgeuse since late 2019,” Dr. Joyce said.
“This prompted speculation it could be about to explode. But our study offers a different explanation.
“We know the first dimming event involved a dust cloud. We found the second smaller event was likely due to the pulsations of the star.”
The research team used modeling to sort out what was going on with the pulsations. They traced 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.
“We could be looking at around 100,000 years before an explosion happens.”
Co-author Dr. László Molnár from the Konkoly Observatory in Budapest says the study also revealed how big Betelgeuse is, and its distance from Earth.
“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,” Dr. Molnár said.
“Once we had the physical size of the star, we were able to determine the distance from Earth. Our results show it’s a mere 530 light-years from us—25 percent closer than previous thought.”
Once they better understood the physical size of Betelgeuse, 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.
Scientists call Betelgeuse a red supergiant because the star is nearing the end of its life. It’s swelling out as it burns through the elements in its core before exploding in a supernova.
Despite being so much closer, the supernova will not impact humans on Earth. However, it will be visible, even during the daytime. Its brightness will outshine our moon.
“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.