There’s never a dull moment in the cosmos. Just when we think we’ve seen it all, astronomers uncover something totally unexpected—like a giant star wrapped in an enormous, expanding cloud of gas and dust.
Red supergiants are stars on the brink of death. As their name implies, they’re much larger than our Sun and have a special role in the galaxy. These stars create and release elements into space—ingredients that help form new stars, and even planets. If you’ve ever looked up at Betelgeuse in Orion or Antares in Scorpius, then you’ve seen two of the Milky Way’s best-known red supergiants.
Here, the bubble of matter photographed by Alma around the red supergiant star DFK 52. In red, gas moving away from us. In blue, gas moving closer. © M. Siebert et al., Alma (ESO/NAOJ/NRAO)
An enormous gas bubble that defies expectations
This time, it’s another red supergiant that’s caught the attention of researchers from Sweden’s Chalmers University of Technology—a star named DFK 52. “It’s more or less a twin of Betelgeuse,” explained Mark Siebert, lead author of the study published in Astronomy and Astrophysics. “And we were completely surprised by the images we got from Alma, the telescope array in Chile.”
What those images revealed is stunning: DFK 52 is surrounded by a chaotic, expanding bubble of stellar material. It’s a swirling mix of gas and dust that weighs as much as the Sun and stretches out 1.4 light-years from the star. That’s way beyond the limits of our entire solar system—and it’s the largest formation of its kind ever recorded in our galaxy.
If the red supergiant DFK 52 were as close to us as Betelgeuse is, its gas bubble would occupy a third of the width of the full Moon in our sky. © jakkapan, Adobe Stock
Could a supernova be next?
Even more intriguing, this vast bubble isn’t standing still—it’s still growing. Researchers believe it may have formed during a massive outburst about 4,000 years ago, when DFK 52 suddenly ejected some of its outer layers. One possible explanation? An unseen companion star might be behind it.
Astronomers are eager to keep watching. With such intense activity, DFK 52 could be heading toward a supernova explosion, becoming the next red supergiant in the Milky Way to go out with a cosmic bang.
Nathalie Mayer
Journalist
Born in Lorraine on a freezing winter night, storytelling has always inspired me, first through my grandmother’s tales and later Stephen King’s imagination. A physicist turned science communicator, I’ve collaborated with institutions like CEA, Total, Engie, and Futura. Today, I focus on unraveling Earth’s complex environmental and energy challenges, blending science with storytelling to illuminate solutions.
