The sun could be late for a ‘superflare,’ study warns

Our Sun could experience an extremely powerful “super-flare” explosion in the coming decades, researchers say.

Stars like our Sun can experience one of these superflares about once every century, according to a new journal article Science. “The new data are a stark reminder that even the most extreme solar events are part of the Sun’s natural repertoire,” said Natalie Krivova, study co-author and solar physicist at the Max Planck Institute for System Research. solar (MPS). .

These superflares are similar to the solar flares we see emitted by our sun, except they are much more powerful, releasing thousands of times the energy of a typical solar flare.

Smaller flares release about 10²⁷ ergs of energy, while larger eruptions, such as the Carrington event of 1859, release around 10³² ergs. Superflares, on the other hand, release energies of around 10³⁴ at 10³⁶ ergs.

For comparison, the atomic bomb dropped on Hiroshima, Japan in 1945 was launched around 10 a.m.²⁰ ergs of energy.

“Between 1996 and 2012, 12 solar flares had bolometric energies >10³² erg, but none were >10³³ erg,” the researchers wrote in the journal.

The only way to measure the Sun’s past activity is to look for evidence of flares in preserved tree trunks and ancient glacial ice. However, these sources did not allow researchers to actually know whether the Sun emits superflares and, if so, how often.

“It is unclear whether the Sun can trigger flares with even higher energies, often called superflares, and if so, how often this might occur,” the researchers wrote in the paper.

In this paper, the researchers used a different approach, measuring the frequency of superflares emitted by sun-like stars around our galaxy to try to get an idea of ​​how often they are released.

“We cannot observe the Sun over thousands of years,” co-author Sami Solanki, director of the MPS, said in the release. “Instead, however, we can monitor the behavior of thousands of stars very similar to the Sun over short periods of time. This helps us estimate how often superflares occur.”

The researchers analyzed data from 56,450 stars and found that a total of 2,889 superflares had been emitted by 2,527 sun-like stars. The stellar data was collected by NASA’s Kepler space telescope between 2009 and 2013.

“In their entirety, the Kepler data provide us with evidence of 220,000 years of stellar activity,” co-author Alexander Shapiro, a researcher at Austria’s University of Graz, said in the release.

This frequency of occurrence of superflares in space indicates that stars with temperatures and variability similar to those of the sun experience powerful superflares about once per century.

This could mean the sun could soon set for such a super-eruption, especially since the Carrington event occurred 165 years ago – the most powerful eruption we have ever recorded – n It wasn’t even powerful enough to be classified as a super-eruption.

The seasons of the Sun

Just as Earth has seasons, our Sun goes from periods of frequent flares to periods of relative calm. This is all part of the approximately 11-year solar cycle.

Learn more in this new episode of NASA’s Illuminate series! pic.twitter.com/NgM0JK6xRx

– NASA Sun and Space (@NASASun) November 8, 2024

“We were very surprised that Sun-like stars are prone to such frequent superflares,” co-author Valeriy Vasilyev, also a researcher at MPS, said in the release.

Solar flares alone can affect Earth by blocking radio communications and altering GPS signals. A more powerful eruption could therefore neutralize them even more seriously. Additionally, solar flares are often, but not always, accompanied by a cloud of solar plasma called a coronal mass ejection (CME), which can cause geomagnetic storms in our atmosphere if it collides with our planet.

“A geomagnetic storm occurs when Earth’s protective magnetic shield is pushed away or eroded by the solar wind,” said Martin Connors, professor of space science and physics at Athabasca University in Canada. News week.

These geomagnetic storms trigger the northern lights and also damage power grids and satellites.

“Due to changes in our magnetic fields and increased currents flowing through them, these storms can induce significant ground currents in electrical infrastructure. For example, power grids. This can result in large and catastrophic power surges , seriously damaging substations and causing power outages,” Daniel Brown, associate professor of astronomy and science communication at Nottingham Trent University in the United Kingdom, said previously. News week.

At the Carrington event, some telegraph operators reported sparks from equipment, causing fires in some cases.

Severe geomagnetic storms caused by a CME associated with a superflare could damage or destroy satellites, and overloads in power grids could cause widespread power outages lasting weeks or months.

However, as the researchers say in the paper, there have been far fewer solar energy particle events throughout Earth’s history than there should have been if the Sun had emitted a super flare at this expected frequency over 100 years.

“It is not entirely clear whether gigantic flares are always accompanied by coronal mass ejections and what the relationship is between superflares and extreme solar particle events. This requires further investigation,” said Ilya Usoskin, co- author of the study from the University of Oulu in Finland, in the press release.

This discovery is useful to scientists because it could help us prepare for extreme geomagnetic storms following a future supereruption.

“(If) our sample of Sun-like stars is representative of the Sun’s future behavior, it is much more likely to produce a superflare than previously thought,” the researchers wrote.

Do you have a tip on a science story that News week should it cover? Do you have a question about solar flares? Let us know via [email protected].

Reference

Vasiliev, V. et al. (2024). Sun-like stars produce superflares about once
per century. Science. 386(6727).