If you don’t know the name, the red supergiant Betelgeuse is one of the most recognizable sights in the skies, the bright red dot on the shoulder of Orion. Already very difficult to overlook, Betelgeuse has gained even more attention in recent years due to major changes in its appearance—unexpected fluctuations in brightness that are still poorly understood. In recent weeks, the star has been shining at times more than 50 percent brighter than usual, attracting renewed attention from amateur sky-watchers and professional astronomers. These people are anticipating and waiting for historic celestial events. As we all know, one day Betelgeuse will end its life explosively in a supernova explosion. And we Earthlings will have a front row seat to this epic cosmic cataclysm from our planetary perch just 650 light-years away.
But will Betelgeuse’s current game of brightening harbingers blow the apex? And what would such a nearby supernova look like?
Despite the ardent wishes of astronomers, it is highly unlikely that anyone alive today will witness a Betelgeuse boom. Based on the star’s brightness, color, size, and estimated age, scientists believe Betelgeuse is in the early stages of fusing helium into carbon. It then needs to fuse to oxygen, then silicon, and finally iron. At this point, Betelgeuse’s core can no longer obtain energy from further fusion reactions, and the star collapses under its own weight, shattering into pieces.
“We know Betelgeuse is about to explode, but ‘soon’ is sometime in the next 10,000 to 100,000 years,” said Jared Goldberg, an astrophysicist at the Flatiron Institute in New York City. ‘, he says. “I’m not going to bet my career on Betelgeuse’s explosion right now.”
But when that day comes, it will be amazing. The first supernova precursors are subtle but unmistakable. A ghostly flood of neutrinos released during the collapse of the star would suddenly flood the Earth and light up detectors all over the world. Shortly thereafter, the real fireworks begin as high-energy photons dig out of the dense cloud of star debris. “What we see is Betelgeuse getting very bright, 10,000, 100,000 times brighter than normal on a week timescale,” Goldberg said. Depending on the strength of the explosion, the supernova remnant will likely be a quarter or half as bright as a full moon and could be concentrated in a single bright spot. Its brightness is visible during the day and bright enough to cast dark shadows. At night.
And the spectacle will last long enough for everyone to see. “It stays bright for a really long time, a long news cycle, a short human life, and an infinitely short star life,” says Goldberg. For astronomers, the explosion and its aftermath are watershed events, offering a unique opportunity for up-close observations that will reveal the rich bounty of amazing discoveries.
Conveniently, Betelgeuse is far enough away that we humans aren’t adversely affected by the explosion itself. But the long history of human supernova observation makes it clear that this event will continue to have an impact. “The sky will change dramatically, and it will be obvious to everyone, and it will have a huge impact around the world,” said Brian Penplays, an astronomer at Soka University of America.
Older stargazers tended to perceive supernovae as bad omens, Penplace said, and in today’s climate of misinformation and science denial, Betelgeuse’s disappearance could elicit a worrying response. It is said that there is a sexuality. “In an age where people are already a little unsettled, an eruption of stars like this will undoubtedly cause a lot of interesting, interesting, and perhaps alarming speculation from different segments of our population.” he says.
We’ve become pretty cut off from heaven, but we can’t ignore Betelgeuse’s supernova. “To be shaken by such a dramatic event from a situation of complete ignorance of the sky would be profound,” says Penplace. “Perhaps we might even rekindle an entire civilization’s interest in astronomy.”
But Betelgeuse’s modern antics don’t have to end in an explosion to be intriguing, Goldberg argues. Its strange oscillations, dimming and flaring, are “proof that there is some really great physics,” he says. “The fact that the stars are pulsing on the human timescale is pretty amazing.”
Astronomers have long known that Betelgeuse brightens and dims periodically. In fact, Australian Aboriginal and ancient Greek records suggest that this cycle was already evident to various cultures on Earth thousands of years ago. In modern times, that cycle lasts about 400 days, but now the star’s brightness fluctuates much faster, around 130 days, said an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, who said the star was says Andrea Dupree, who tracks
And Betelgeuse’s current dynamics appear to be related to the so-called great dimming of late 2019 and early 2020, which scientists attributed to the star’s massive gas and dust mass emissions. I think it is. “Imagine taking out a chunk of material, and everything else will flow in and flop around,” says Dupree. The resulting turbulent plasma and magnetic quagmire may help explain why the star is now much brighter than predicted for its 400-day cycle.
Dupree likens unplanned brightening to a washing machine that rattles off balance. “I think what’s happening is that the top tier is having trouble getting back to normal,” she says. “I hope to eventually get back to 400 days, but I’m struggling right now.”
