The red giant star Betelgeuse could explode much earlier – researchers have a new theory

The red giant Betelgeuse is set to explode as a supernova within the next 100,000 years. A new study now wants to show that the eruption could have come much earlier.

Sendai – About 650 light-years from Earth is a dying star: Betelgeuse. This red giant star, known as the left “shoulder star” in the constellation Orion, is about to explode in a supernova. However, “just before” always refers to astronomical timescales: astronomers assume that it could be another 100,000 years before Betelgeuse ends up as a luminous supernova.

Now, new research reveals that things may be very different, and Betelgeuse may explode much sooner than previously thought. Hideyuki Sayo and his team from Tohoku University in Sendai, Japan, studied the pulse of Betelgeuse extensively and came to a surprising conclusion. The study was on a prepress server ArXiv published It is currently undergoing comprehensive peer review prior to publication in the journal Monthly Notices of the Royal Astronomical Society It will be published.

The red giant star Betelgeuse could explode sooner than thought

The star Betelgeuse has been attracting attention for some time: during the turn of the year 2019/2020, the normally bright star dimmed significantly. There were suspicions that it might be about to explode, but several studies have refuted this assumption. Before its eclipse, the star released a huge bubble of gas, moving away from Betelgeuse and eclipsing the star for a while. In the spring of 2023, Betelgeuse suddenly experienced a significant increase in brightness — and once again there was speculation about an imminent supernova.

To conduct the new study, Saio’s team examined the pulse of Betelgeuse. Like many other stars, the outer layers of Orion’s Shoulder are also pulsating. This results in relatively regular fluctuations in brightness, with the most pronounced periodic fluctuations lasting 2,200 days and 420 days, respectively. Until now, researchers have looked at the shorter period of time as the star’s “heartbeat” and interpreted this as an indication that Betelgeuse is a younger star. But what if this assumption is wrong and instead the 2200 day pulse is in fact a “heartbeat”?

Is the giant star Betelgeuse bigger than previously thought?

If the 2200-day pulse turns out to be the main pulse, the initial result would be that Betelgeuse must be larger than previously thought. Current research assumes that the star’s diameter is 800 to 900 times that of the Sun. However, if the 2,200-day pulse were the main pulse, this would mean the star’s diameter would be even 1,200 suns. At the same time, it indicates that the star has a longer life cycle than previously thought.

Star luminosity is initially created when hydrogen in the core fuses into helium. Once hydrogen is used up, helium becomes carbon, which in further reactions turns into heavier elements as stellar life progresses. Using computer simulations, Saio and his research team have shown how stars evolve from formation to aging and at what stages of their lives they pulsate and how. The different stages of development are examined in detail.

Is the star Betelgeuse much older than previously thought?

Based on these simulations, all of the observed pulsations of Betelnut can be assigned to a much more advanced stage of its stellar life than previously thought: the stage when the star is burning carbon. “When the carbon in the core runs out, a core collapse leading to a supernova explosion is expected within a few tens of years,” stresses the study’s research team. However, the research team cannot predict the exact timing of the likely supernova explosion, Kef Sayo opposite the magazine sky and telescope compressed. “We only estimate that the time taken for carbon depletion may be less than a few hundred years.”

So an immediate supernova explosion from Betelgeuse is still not likely, but it is likely that it will happen before the next 100,000 years. However, not all researchers are satisfied with the new accounts. Morgan MacLeod, an astrophysicist at the Astrophysical Center at Harvard and Smithsonian University who studies pulsars himself, says the new findings are not consistent with other observations of the star. In particular, given the 2,200-day cycle as the “main pulse,” the red giant would grow to hyperboloid size.

Betelgeuse supernova explosion: critique of the new study

“I don’t think the explanation put forward by Sayo and colleagues is in any way out of the question,” says MacLeod. sky and telescope. “But there are some potential questions it raises that at first glance seem at odds with the data.” It looks like the Betelgeuse star isn’t losing its charm any time soon. Susanne Wampfler, an astrophysicist from the University of Bern, builds anticipation of the supernova explosion of Betelgeuse against the revolutionary front Aptly put: “It could happen basically any day or not for a very long time.”

Machine assistance was used in this editorial article. The article was carefully screened by editor Tanya Banner before it was published.