Astronomer Joseph Callingham and his team have observed for the first time a clear signal from a giant burst from a star outside our solar system. This would have a devastating impact on any unfortunate planet orbiting the star.
An international team of astronomers, led by ASTRON (the Netherlands Institute for Radio Astronomy) and the Observatoire de Paris-CNRS, discovered a short, intense burst of radio waves coming from a nearby red dwarf star, 130 light-years away, using Europe's powerful LOFAR radio telescope. This burst is similar to a so-called Coronal Mass Ejection (CME) as we know it from our sun.
First clear radio detection
CMEs are large bursts of magnetised plasma originating from stars and play an important role in shaping space weather in our solar system - such as causing the beautiful auroras we see on Earth. Although it has long been expected that CMEs also occur on other stars, this is the first time one has been observed via its characteristic radio signal.
'For the first time, we have evidence that hot plasma from another star has been ejected into interplanetary space,' says Callingham, author of the study. 'This gives us the opportunity to go beyond theories based solely on the Sun.'
'We show that this eruption would be devastating for a planet orbiting such a star,' says Callingham. 'The CME has the power to compress an Earth-like magnetosphere all the way down to the planet's surface, temporarily stripping away its protective atmosphere. That means such flares could determine whether a planet is potentially habitable.'
LOFAR's unique capabilities
Planets with a mass similar to that of Earth are most common around red dwarf stars, stars with 10 to 50 per cent of the Sun's mass. Because their habitable zones, where liquid water can exist on the surface, are very close to the star, these planets are likely to be exposed to much more intense stellar storms than Earth.
'This discovery shows that violent space weather is not unique to our Sun,' says co-lead author Cyril Tasse of the Observatoire de Paris. 'We now know that planets around small stars are often hit by powerful eruptions. Thanks to the advanced data processing methods developed at the Observatoire de Paris, we can now measure how extreme these conditions really are.'
The discovery opens a new window on the study of space weather in other solar systems, with important implications for the search for life. Future observatories, such as the Square Kilometre Array, will enable astronomers to discover many more of these stellar eruptions and better understand how they determine the fate of exoplanets.
Read the scientific publication 'Radio burst from a stellar coronal mass ejection' in Nature.
ASTRON is the Dutch institute for radio astronomy. They develop innovative technologies and manage world-class radio astronomy facilities. These include the Westerbork Synthesis Radio Telescope and the Low Frequency Array (LOFAR), the world's largest radio telescope. In addition, they conduct fundamental astronomical research. ASTRON also coordinates the Dutch contribution to the construction of the Square Kilometre Array (SKA). ASTRON is based in Dwingeloo and collaborates with universities and research institutes worldwide to push the boundaries of our understanding of the universe.
