Astronomers using the European Space Agency’s XMM-Newton space observatory and the LOFAR telescope spotted an explosion of material thrown into space by another star, according to a study published in Nature. The burst was powerful enough to strip away the atmosphere of any planet in its path.
The burst was a coronal mass ejection (CME), a common phenomenon from the sun. During a CME, large amounts of material are ejected from the sun into the surrounding space. These expulsions shape space weather, such as the auroras we see on Earth, and can chip away at the atmospheres of any nearby planets.
But while CMEs are common in the Sun, this was the first time we spotted one on another star. “Astronomers have wanted to spot a CME on another star for decades,” said Joe Callingham of the Netherlands Institute for Radio Astronomy (ASTRON). “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, it produces a shock wave and a burst of radio waves. This short, intense radio signal was picked up by Joe and colleagues and found to come from a star lying around 40 light-years away. This is just under 15 times the diameter of the Solar System, which is close by cosmic standards. “This kind of radio signal just wouldn’t exist unless material had completely left the star’s bubble of powerful magnetism,” added Callingham. “In other words: it’s caused by a CME.”
The star in question is a red dwarf, which is a type of star cooler and smaller than the Sun. This one in particular has roughly half the mass, it rotates 20 times faster, and has a magnetic field 300 times more potent than the sun.
The radio signal was detected with the Low Frequency Array (LOFAR) radio telescope, using new data-processing methods developed by co-authors Cyril Tasse and Philippe Zarka at the Observatoire de Paris-PSL. The team then used ESA’s XMM-Newton to determine the star’s temperature, rotation, and brightness in X-ray light. This was essential to interpret the radio signal and figure out what was happening.
“We needed the sensitivity and frequency of LOFAR to detect the radio waves,” said co-author David Konijn, a PhD student working with Joe at ASTRON. “And without XMM-Newton, we wouldn’t have been able to determine the CME’s motion or put it in a solar context, both crucial for proving what we’d found. Neither telescope alone would have been enough – we needed both.”
The researchers calculated that the CME was moving at 2400 km per second, a speed observed in only 1 of every 20 CMEs on the Sun. The ejection was both fast and dense enough to completely strip away the atmospheres of any planets closely orbiting the star.
This ability of the CME to strip the atmospheres of surrounding planets is an exciting discovery that could help us understand life on other planets. The distance to its parent star controls a planet’s habitability for life. This defines the ‘habitable zone’, a region where liquid water can exist on the surface of planets with suitable atmospheres. This is a Goldilocks scenario: too close to the star is too hot, too far is too cold, and in between is just right.
But what if that star regularly throws out dangerous eruptions of material and triggers violent storms? A planet bombarded by these powerful ejections may lose its atmosphere entirely, leaving a barren rock behind – an uninhabitable world, despite its orbit being in the right place.
“This work opens up a new observational frontier for studying and understanding eruptions and space weather around other stars,” added Henrik Eklund, an ESA research fellow based at the European Space Research and Technology Centre (ESTEC) in Noordwijk, The Netherlands. “We’re no longer limited to extrapolating our understanding of the Sun’s CMEs to other stars. It seems that intense space weather may be even more extreme around smaller stars – the primary hosts of potentially habitable exoplanets. This has important implications for how these planets keep hold of their atmospheres and possibly remain habitable over time.”
Callingham, J.R., Tasse, C., Keers, R. et al. Radio burst from a stellar coronal mass ejection. Nature (2025). https://doi.org/10.1038/s41586-025-09715-3