October 4, 2023

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No, Betelgeuse will not go supernova in “dozens of years”

No, Betelgeuse will not go supernova in “dozens of years”

The expiration date of Betelgeuse, a dying massive star about 642 light-years from Earth, is a hot topic in astronomy because of the star’s extraordinary size and stage of its life cycle.

Betelgeuse has a mass between 10 and 20 times that of our Sun, and its radius is about 900 times larger. It burns quickly, and soon you will die (in the cosmic sense).

When stars die, they expel most of their material out into the universe in a gorgeous explosion called a supernova. If the conditions are right, the supernova leaves a quiet stellar nebula behind.

Our sun will go through this process in about 5 billion years, but Betelgeuse is much closer to its end. And while the stars in the distant universe Going supernova all the timeBetelgeuse in our galaxy, basically on our doorstep in cosmological terms.

Earlier this month, a team of researchers published a dossier Sheet to arXiv prepress server. In the paper, the team hypothesized that Betelgeuse was already in the “late stage of primary carbon combustion,” and was therefore a strong candidate for the most imminent supernova in our galaxy. “According to this figure, the core will collapse within a few tens of years after carbon is depleted,” the researchers wrote.

on social mediaSome have taken this to mean that a supernova will occur in the next century, or even in the next few decades. But burning carbon is a slow process, even if Betelgeuse-Which we are allowed to write as many times as we want without supernatural Ramificationsat that point.

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In an email to Gizmodo, Hideyuki Saio, an astronomer at Tohoku University and lead author of the preprint, tells Gizmodo that the team expects the supernova to occur “in less than a few hundred years.”

Betelgeuse (upper right, orange) in the image of the constellation Orion.

To some extent, the buzz is about Saio The revised timeline is a casualty of people not reading closely his team’s conclusions paper. But even so, scientists unaffiliated with the research say the team’s model doesn’t explain the star’s position.

Emily Hunt, an astronomer at the University of Heidelberg who was not affiliated with the latest paper, said in a phone call to Gizmodo. “Just because a model explains feedback, it doesn’t mean the model is correct.”

Hunt added, “It’s really unfortunate that we’ve seen so many people take this paper and take it as gospel, when in reality it’s just one interpretation of the notes.”

Betelgeuse is very small –About 10 million years ago—but it will burn much faster than the sun. Over the course of its evolution, Betelgeuse may have changed color in the night sky, which explains why Old descriptions of the star described the red ball of gas as being more yellow.

SPHERE images show the Great Dimming of Betelgeuse.

In recent years, Betelgeuse has been subject to an unusual amount of activity, spurring debate about when the fateful supernova occurred. In 2019, the star had a surface mass ejection, ejecting from its surface about 400 billion times more than the mass of one of our sun’s coronal ejections (CMEs), According to NASA.

The giant star is greatly dimmed. The period is known as the Great Dimming. Astronomers now believe that the cause of the dimming Stellar burps scatter dust from the star, partially obscured by Betelgeuse From the point of view.

said Miguel Montargues, an astronomer at the Sorbonne and one of the authors of the book 2021 Leaf in Nature describes the dust of Betelgeuse, in an email to Gizmodo. “However, if Betelgeuse had a previous exchange of matter with a companion hidden within or near the star itself, or with a previously dead companion, we might encounter a non-unilateral evolution of a star with many uncertain parameters. This would leave open discussion of its evolution.”

Montargis said the team’s model requires a larger solar radius (about 1,300 suns) than observed (about 800 to 900 solar radii), and if Betelgeuse had shrunk as much as the team claimed, astronomers would see matter surrendering to the star.

Montargis added, “I have to stress that with our current knowledge, assuming the non-interacting star scenario from which we have no reason to get rid of, Betelgeuse must be in a helium core, and it should explode in at least tens of thousands of years.”

Illustration showing how ejection of material obstructed Earthlings' view of Betelgeuse by dust grains.

Worryingly, the burning phase of Betelgeuse – that is, the element the star is currently using as fuel – is not clear from the observations. As stars progress through their life cycles, they burn off different fuels (such as hydrogen and helium), with the combustion of carbon occurring in the star’s death throes.

“One of the difficulties with this problem is that carbon-burning Betelgeuse might look exactly as it does now — and that’s why there’s this controversy,” Meredith Joyce, an astronomer at the Konkoli Observatory in Hungary, said in an email to Gizmodo. “If a star is undergoing helium combustion versus carbon combustion simply by observation, we can stop arguing!”

Along with two co-authors Joyce Post a comment Refutation of the Saio team’s paper in the American Astronomical Society’s research notes. Joyce’s team hypothesized that the Saio team used an incorrect Betelgeuse radius in making their claims, and the way they designed the star ultimately resulted in an inaccurate (i.e. too close) timeline for Betelgeuse’s end.

Joyce added, “Our team confirms that the time of Betelgeuse until the supernova occurred is 100,000 years, a number that comes (mainly) from the state of helium burning.” It wouldn’t be scientific to be more precise than that; There are so many unknowns in stellar modeling.”

All agree that more specific measurements of the distance of Betelgeuse will be useful in determining a star’s true brightness and, therefore, its place in its life cycle.

Everyone wants to see a star die, which may be why people get so excited about the terms “a few dozen years” in Saio et al. paper. When the research found that Betelgeuse would go supernova in a faster time frame than predicted in previous papers — and time scales of centuries very close in stellar terms — it was bound to create an even bigger buzz than the research confirming that Betelgeuse still has a way to go. long to cut it.

But if you’re eager to see a supernova, you’d better look no further than our local giant. Montargis said the stars eta Carinae and VY Canis Majoris (which the Minnesota Astrophysical Institute calls “Betelgeuse on steroids”) are the best bets for the next supernova in our galaxy.

Or you can always wait for space telescopes like Webb or Hubble To image the next supernova, somewhere in the outermost universe. Other telescopes – such as those in The Rubin Observatory in Chile will open soon—it will aim to image the night sky continuously, hoping to capture fleeting events like the start of a supernova as they happen.

More: How do we know when the sun will die?