Supergiant star’s gigantic bubble surprises scientists

Astronomers have found an enormous and increasing bubble of fuel and dirt surrounding a purple supergiant star—the most important construction of its sort ever seen within the Milky Way. The bubble, which incorporates as a lot mass because the solar, was blown out in a mysterious stellar eruption about 4,000 years in the past. Why the star survived such a robust occasion is a puzzle, scientists say.

The outcomes have been accepted for publication within the journal Astronomy and Astrophysics. It is available on the arXiv preprint server. The crew was led by Mark Siebert, from Chalmers University of Technology. Using the ALMA radio telescope in Chile, the researchers noticed the star DFK 52—a purple supergiant just like the well-known star Betelgeuse.

“We got a big surprise when we saw what Alma was showing us. The star is more or less a twin of Betelgeuse, but it’s surrounded by a vast, messy bubble of material,” says Siebert.

The bubble, a posh of clouds of fuel and dirt, weighs as a lot because the solar, and extends out 1.4 gentle years from the star. That’s tens of hundreds of occasions wider than our personal photo voltaic system.

If the star was as near us as Betelgeuse is, the bubble would seem to span a 3rd of the complete moon’s width within the sky.

ALMA’s radio observations let astronomers measure the movement of molecules within the cloud, revealing that the bubble is increasing. They imagine it was shaped when the star abruptly ejected a part of its outer layers in a robust explosion only a few thousand years in the past.

“The bubble is made of material that used to be part of the star. It must have been ejected in a dramatic event, an explosion, that happened about 4,000 years ago. In cosmic terms, that’s just a moment ago,” says Elvire De Beck, astronomer at Chalmers.

The galaxy’s subsequent supernova?

Why DFK 52 shed a lot mass with out exploding as a supernova remains to be unclear. One risk is that the star has a hidden companion that helped it eject its outer layers.

“To us, it’s a mystery as to how the star managed to expel so much material in such a short timeframe. Maybe, like Betelgeuse seems to, it has a companion star that’s still to be discovered,” says Siebert.

Red supergiants like DFK 52 are nearing the ends of their lives and are anticipated to ultimately explode as supernovae. Could this star be subsequent?

“If this is a typical red supergiant, it could explode sometime in the next million years. We’re planning more observations to understand what’s happening—and to find out whether this might be the Milky Way’s next supernova,” says De Beck.