Astronomers have, for the first time, conclusively detected a colossal coronal mass ejection erupting from a star beyond our Solar System – a violent blast of charged particles so extreme it could strip nearby planets of their entire atmospheres.
A milestone beyond the Sun
For decades, scientists have suspected that other stars unleash the same kind of explosive plasma storms seen on the Sun, but until now they had only indirect hints. The new detection finally confirms that coronal mass ejections (CMEs) are not unique to our star, marking a major breakthrough in stellar physics and exoplanet research.
The event was observed on a nearby red dwarf star, delivering the first definitive proof that material can be blasted completely out of another star’s magnetic grip and hurled into interstellar space. The finding ends a decades‑long astronomical quest to catch such a stellar storm in the act beyond our Solar System.
What exactly is a coronal mass ejection?
A coronal mass ejection is a titanic eruption in which a star hurls vast clouds of magnetised plasma from its outer atmosphere, or corona, into surrounding space. On the Sun, CMEs can trigger dazzling auroras on Earth, interfere with satellites, and pose radiation risks to astronauts by dramatically disturbing space weather.
These outbursts can also erode the atmospheres of planets, gradually stripping away protective layers of gas that are vital for surface water and, potentially, life. Until now, however, scientists had to extrapolate from the Sun, lacking a clean, confirmed example of a CME from another star to test their models.
The star that exploded: a nearby red dwarf
The newly detected stellar storm came from a small, active red dwarf star relatively close in cosmic terms. One report places the culprit about 40 light‑years away, while others describe similar violent events from red dwarfs around 130 light‑years distant, underlining that such stars can be ferocious space‑weather engines.
This red dwarf has roughly half the mass of the Sun, but rotates around 20 times faster and harbours a magnetic field roughly 300 times stronger, conditions that can supercharge stellar activity. Red dwarfs are among the most common hosts of exoplanets, including many worlds considered potentially habitable based on their distance from the star.
How astronomers caught the blast
The breakthrough hinged on a powerful one‑two punch of radio and X‑ray observations. Astronomers first picked up a short, intense burst of low‑frequency radio waves using the LOFAR (Low Frequency Array) radio telescope in Europe, a signal signature closely associated with CMEs.
When a CME ploughs through a star’s outer layers and into space, it drives a shock wave that emits a distinct type of radio burst. The team identified such a burst coming from the red dwarf, a kind of signal that “just wouldn’t exist unless material had completely left the star’s bubble of powerful magnetism,” as lead author Joe Callingham put it.
To interpret the radio flash, researchers turned to the European Space Agency’s XMM‑Newton X‑ray space observatory. XMM‑Newton measured the star’s temperature, rotation and X‑ray brightness, data that were crucial to confirm that the observed radio burst really came from a CME instead of some other kind of flare activity.
A monster eruption: 2,400 km per second
Once the team reconstructed the event, the scale of the explosion became clear. The CME was tearing through space at around 2,400 kilometres per second – a speed rarely seen even on the Sun. Studies note that such extreme velocities occur in only a small fraction of solar CMEs, making this eruption an outlier even by our star’s standards.
The blast was not only fast but also dense, packing enough material and energy to completely strip the atmosphere from any planet orbiting close to the star. One estimate suggests the event was at least 10,000 times more violent than typical solar storms recorded on the Sun, underscoring just how hostile such systems could be to nearby worlds.
Threat to exoplanet atmospheres and habitability
The discovery has profound implications for the search for life beyond the Solar System. Habitability is often defined by whether a planet lies in the so‑called “Goldilocks zone,” where temperatures allow liquid water to exist, but this event shows that location alone is not enough if the atmosphere cannot survive.
Red dwarfs are prime targets in the hunt for Earth‑like exoplanets because they are small, numerous, and easier to study than Sun‑like stars. Yet this kind of extreme space weather could strip the atmospheres of planets even if they sit at just the right distance for liquid water, potentially leaving many red‑dwarf worlds barren and airless.
Some researchers warn that intense, frequent CMEs around smaller stars might systematically erode atmospheres over time, limiting the window in which life could arise or endure. On the other hand, understanding how often such events occur could help astronomers sift out the most promising planetary systems that enjoy calmer conditions.
A new tool to probe stellar storms
Capturing this CME opens a new era in studying how stars sculpt their surrounding planetary systems. The combination of LOFAR’s sensitive low‑frequency radio capabilities and XMM‑Newton’s X‑ray vision provides a template for hunting similar events on many other stars.
By systematically searching for the radio fingerprints of CMEs and cross‑checking with X‑ray data, astronomers can begin to map how space weather behaves across different types of stars, from small red dwarfs to young Sun‑like stars. This will help refine models of atmospheric loss, magnetic shielding, and long‑term planetary evolution, all of which feed into the big question of where life can survive.
Decades‑long search finally resolved
Scientists have been trying to pin down a clear CME beyond the Sun for many years, but previous reports were either ambiguous or incomplete. Flares, which are sudden flashes of radiation, can often be seen on other stars, but proving that large amounts of plasma actually escaped into space remained frustratingly elusive.
The new study, published in the journal Nature, is being hailed as the first unambiguous confirmation that a stellar CME was seen in real time, from its radio shock signature to its physical properties. ESA scientists emphasise that the result is a testament to international collaboration and sophisticated data‑processing techniques developed to comb through the huge LOFAR datasets.
What comes next for astronomers
Researchers now plan to expand their search to more stars, including those known to host potentially habitable exoplanets. By tallying how often violent CMEs occur and how powerful they are, they hope to build a statistical picture of which planetary systems are most likely to keep their atmospheres over billions of years.
Future radio facilities and upgrades to existing arrays will make it easier to catch the fleeting radio bursts that betray a CME’s passage, even from stars far more distant than this red dwarf neighbour. Space‑based observatories, meanwhile, will continue to provide the X‑ray context needed to interpret these outbursts and refine models of stellar magnetism and space weather.
Why this matters for Earth
Although this CME erupted on a distant star, the discovery feeds back into understanding the Sun and the risks it poses to Earth. Comparing solar CMEs to truly extreme stellar events helps place our star’s behaviour on a broader cosmic scale, highlighting how relatively moderate – or potentially how dangerous – future solar storms could be.
The work also underscores how crucial Earth’s own magnetic field and atmosphere are in shielding life from high‑energy particles and radiation. As astronomers continue to search for planets that might resemble Earth, the lesson from this violent eruption is clear: a gentle star and a protected atmosphere may be just as important as the right orbital distance for life to thrive.
