Astronomers using the European Space Agency’s XMM-Newton space observatory and the LOFAR telescope have definitively spotted an explosive burst of material thrown out into space by another star – a burst powerful enough to strip away the atmosphere of any unlucky planet in its path.The burst was a coronal mass ejection (CME), eruptions we often see coming from the Sun. During a CME, massive amounts of material are flung out from our star, flooding the surrounding space. These dramatic expulsions shape and drive space weather, such as the dazzling auroras we see on Earth, and can chip away at the atmospheres of any nearby planets.

But while CMEs are commonplace at the Sun, we hadn’t convincingly spotted one on another star – until now. “Astronomers have wanted to spot a CME on another star for decades,” says Joe Callingham of the Netherlands Institute for Radio Astronomy (ASTRON), author of the new research published in Nature. “Previous findings have inferred that they exist, or hinted at their presence, but haven’t actually confirmed that material has definitively escaped out into space. We’ve now managed to do this for the first time.”

As a CME travels through the layers of a star out into interplanetary space, it produces a shock wave and associated burst of radio waves (a type of light). This short, intense radio signal was picked up by Joe and colleagues and found to come from a star lying around 130 light-years away.

“This kind of radio signal just wouldn’t exist unless material had completely left the star’s bubble of powerful magnetism,” adds Joe. “In other words: it’s caused by a CME.”