A recent study shows that Betelgeuse’s recent strange dimming is due to a giant cloud of matter that the supermassive star has blown into space.
Bright Star Betelgeuse, forming the shoulder of the constellation Orion (The Hunter), about 11 times more massive than the sun but 900 times heavier. That swelling showed that Betelgeuse was on the verge of death, which would take place in the form of a massive supernova explosion.
In the fall of 2019, Betelgeuse begins to fade significantly, takes about 2/3 of the brightness in February. This dramatic drop prompted speculation that a star̵7;s collapse could be imminent – perhaps just a few weeks away. (In our view, Betelgeuse is about 500 light years from Earth anyway, so everything we see with the star today happened centuries ago.)
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But dramatic sky performances didn’t happen: Betelgeuse powered the dimming phase and returned to normal brightness in May this year. The rebound has sparked a new round of speculation, this time about the cause of the blurring. Some scientists think the bleak situation is due Dust clouds block the light, for example, while others speak large star spots on Betelgeuse’s surface is likely to be blamed.
A new study supports the dust hypothesis, but adds another point – Betelgeuse himself appears to have flown into the cloud.
The researchers studied the star in 2019 and 2020 using the NASA logo The Hubble Space Telescope. Hubble observations from September to November 2019 show that a large amount of matter is moving from the Betelgeuse surface out into its atmosphere at a terrible rate – about 200,000 miles / hour (320,000 km / h).
During this three-month outbreak, Betelgeuse lost about twice as much matter into space from its southern hemisphere as usual, according to team members. (Betelgeuse’s background loss rate is substantial – about 30 million times that, by the way our sun.)
Extremely hot plasma like this, or electrically charged gas, cooled significantly after traveling millions of miles from Betelgeuse, condenses into dust particles and forms a cloud-blocking light, the scientists propose in New research, published online today (August 13) in the Journal of Astrophysics.
“This material is two to four times brighter than a star’s normal brightness,” said lead author Andrea Dupree, associate director of the Center for Astrophysics at Harvard University and the Smithsonian Institution in Cambridge, Massachusetts.
“And then, about a month later, the southern part of Betelgeuse visibly dimmed as the star faded,” Dupree said. “We thought it was possible that a dark cloud was the result of a stream that Hubble detected.”
Additional Hubble observations supported this interpretation. Ultraviolet light data shows that Betelgeuse’s outer atmosphere returned to normal by February 2020, although the dimming at visible wavelengths continues.
It’s not clear what caused the explosion in the fall of 2019. But Dupree and study co-author Klaus Strassmeier, of the Leibniz Potsdam Institute for Astrophysics in Germany, suggest it is likely driven by pulses. Betelgeuse’s regularity.
The supermassive star expands and contracts with a period of 420 Earth days. Strassmeier measured the velocity of the gas on Betelgeuse’s surface with an automatic telescope at the Leibniz Institute and found that the explosion occurred during the star’s expansion phase.
Dupree plans to continue studying Betelgeuse with Hubble, and other astronomers will certainly follow closely on this star. The supergiant is already interesting enough in its current state, and the observations about it will be of even more importance if Betelgeuse thrives in the near future.
“Nobody knows what a star does right before it goes supernova, because it has never been observed, “said Dupree.” Astronomers have sampled the stars for perhaps a year before they became supernovae, but not for days or weeks before it happened. But the likelihood that a star will soon become a supernova is quite small. “
Mike Wall is the author of “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.