The sun may be spewing out giant solar flares more often than we thought.

The sun may emit very powerful radiation more often than we thought. Surveys of sun-like stars show that these “superflares” occur as frequently as once every 100 years, and can bring particle storms with devastating consequences for electronics on Earth. The last major solar storm to hit Earth was 165 years ago, so we may soon face another, but it’s unclear how similar our Sun is to these other stars.

Although direct measurements of solar activity began only in the mid-20th century, there is also early evidence of solar storms. We know that in 1859 our star produced an extremely powerful solar flare, an explosion of light radiation. These are often associated with subsequent coronal mass ejections (CMEs), which are bubbles of magnetized plasma particles launched into space.

The flare was actually followed by a CME that created a powerful geomagnetic storm that struck the Earth, which was recorded by astronomers at the time and is now known as the Carrington Event. If this were to happen today, communications systems and power grids could be disrupted.

There is also evidence that much more powerful storms occurred on Earth long before the Carrington event. Assessments of radiocarbon from tree rings and ice cores show that the Earth has been bombarded with very high-energy particles, sometimes over several days, but it is unclear whether this came from a one-time large solar explosion or occurred over several times. Smaller things. It’s also unclear whether the Sun can produce such large flares and particle storms in a single explosion.

The frequency of these signs on Earth, as well as the superflares that astronomers have recorded from other stars, suggests that these giant explosions tend to occur every hundreds to thousands of years.

now, Ilya Usokin A team of researchers from the University of Oulu in Finland examined 56,450 stars and found that stars like our sun appear to produce superflares much more frequently.

“Superflares from Sun-like stars occur much more frequently than previously thought, occurring approximately once every century or two,” Usoskin says. “If we believe these predictions about the Sun are correct, we would expect a superflare on the Sun approximately every 100 to 200 years, and a severe solar storm as we know it would occur approximately once every 1,500 to 2,000 years. I expect it. “There is a discrepancy.”

Usoskin and his colleagues used the Kepler Space Telescope to measure the brightness of stars and detected a total of 2,889 superflares from 2,527 stars. The energy of these flares was between 100 and 10,000 times that of the Carrington event, the largest ever measured on the Sun.

We still don’t know whether such large flares produce the kind of large particle events for which there is evidence on Earth, but current solar theories say they cannot explain such large flares. “This opens up the question of what we are actually seeing,” he says.

“As a stellar flare survey, it’s really impressive,” he says. Matthew Owens from the University of Reading, UK. “They certainly have a new way of detecting flares with improved sensitivity.”

Owens says it’s harder to discern how much this tells us about the sun’s flashing activity. This is partly because it is difficult to accurately measure the rotation speed of other stars. “The devil is in the details,” he says.

“Rotation rates are important because they are linked to how stars produce magnetic fields, and magnetic fields are linked to flare activity,” says Owens.