Astronomers have spotted something extraordinary in our galaxy—a huge, expanding bubble of gas and dust around a red supergiant star.
It’s the largest bubble of its kind ever seen in the Milky Way, and it’s leaving scientists with more questions than answers.
The star, called DFK 52, is a massive red supergiant similar to the famous Betelgeuse.
Red supergiants are some of the largest stars in the universe, nearing the end of their lives.
Using the ALMA radio telescope in Chile, a team led by Mark Siebert from Chalmers University of Technology discovered that DFK 52 is surrounded by an enormous, cloud-filled bubble that stretches an incredible 1.4 light-years across.
To put that into perspective, it’s tens of thousands of times wider than our solar system.
This bubble is not just big—it’s heavy too. It contains as much mass as our Sun and appears to have been created about 4,000 years ago when the star erupted, ejecting part of its outer layers into space. Despite the massive outburst, the star somehow survived the event, which has left scientists puzzled.
“We were really surprised when we saw the ALMA images,” Siebert said. “The star is like a twin of Betelgeuse, but its surroundings are incredibly messy—a vast bubble of material blown out in some dramatic way.”
If DFK 52 were as close to Earth as Betelgeuse, the bubble would take up about a third of the Moon’s width in our sky—easily visible to the naked eye. ALMA’s detailed observations allowed astronomers to measure the movement of molecules in the gas and dust, showing that the bubble is still expanding.
Elvire De Beck, another astronomer from Chalmers, explained that the ejected material was once part of the star itself. “It must have been thrown out in a huge explosion, but in cosmic terms it happened only a moment ago—just a few thousand years back.”
Why the eruption happened without triggering a supernova is still a mystery. One theory is that DFK 52 might have an unseen companion star that helped pull away its outer layers. Betelgeuse, for example, is suspected to have such a companion, which could influence its strange behavior.
Red supergiants like DFK 52 are ticking cosmic time bombs. Eventually, they end their lives in spectacular supernova explosions. Could this be the Milky Way’s next big blast? Possibly—but don’t hold your breath. Scientists say if DFK 52 is an average red supergiant, it might explode anytime within the next million years.
For now, the team is planning more observations to understand how such a massive bubble formed, why the star survived, and whether we’re looking at one of the galaxy’s most dramatic pre-supernova displays.
Source: KSR.
