Violent superflares explode from sun-like stars every 100 years

High-energy, powerful and violent stellar explosions called “superflares” have been found to erupt from stars like the sun about once every 100 years, making these explosions much more common than scientists thought.

Solar flareshigh-energy radiation bursts can have serious effects on Earth, with the potential to damage communications systems and energy infrastructure.

However, solar flares are only the tip of the iceberg in terms of bursts of energy that stars can emit. A more extreme phenomenon is “super flare,” an explosion that can be tens of thousands of times more powerful than the “typical” solar flare.

One of the most violent solar storms on record was The Carrington Event of 1859. During this storm, telegraph networks in Europe and North America collapsed. Worryingly, the Carrington event – as extreme as it was – released only 1% of the energy that could be emitted during an explosion.

While astronomers have been aware of the existence of these alarmingly powerful eruptions from SUNsuch outbreaks had, until now, appeared to be rare.

“Superflares on stars similar to our sun appear once a century. This is 40 to 50 times more common than previously thought,” study team member Valeriy Vasilyev, a scientist at the Max Planck Institute for Solar System Research in Germany, told Space.com. “If our sample of sun-like stars is representative of the sun’s behavior, our star is much more likely to produce a superflare than previously thought.

“Everything about this discovery was surprising.”

The team’s research was published Thursday (December 12) in the journal Science.

Why turn to the stars to study the sun?

This year, the sun has been particularly turbulent, blasting Earth with typically powerful solar storms and intensifying auroral displays as a reminder of how violent our star can be. While scientists have been able to study this behavior and collect invaluable data, this represents the sun’s behavior on a small part of it. 4.6 billion years of life yet.

There is a record of the sun’s long-term behavior and its outbursts sealed in prehistoric trees and in glacial ice which is thousands of years old. However, these indirect methods are not able to show us how often the sun has thrown a major tantrum and launched a superflare.

In search of this information, Vasilyev and colleagues turned to a sample of thousands of other stars, which they determined were similar to the Sun in their stellar class and behavior.

“We can’t observe the sun for thousands of years,” team member Sami Solanki, director of the Max Planck Institute for Solar System Research, said in a statement. “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.”

solar storm erupting from the sun's surface in a great filament of fire.

A solar storm erupting from the sun. (Image credit: Science Photo Library via Getty Images)

Vasilyev explained that the team took into account an improved understanding of stars with sun-like behavior or “near-solar variability” provided by recent research. Then they turned to data collected by NASA The Kepler Space Telescope between 2009 and 2013. This is the equivalent of 220,000 years of stellar activity.

Stars that appeared to be particularly “close relatives” of the sun were selected from this data set.

“Using this improved understanding, we have selected a new solar-stellar comparison sample that is much larger and more representative of the Sun than previous samples,” Vasilyev continued. “We also developed a new method to detect flares and locate them with subpixel resolution, taking into account instrumental effects.”

The team observed 2,889 super flares on 2,527 of the 56,450 stars observed. This equates, on average, to a sun-like star producing a superflare every 100 years or so.

According to Vasilyev, the team’s results also indicated for the first time that the frequency of solar and stellar flares is consistent with each other. This suggests that as well mechanism it generates flares on the sun and sun-like stars.

A warning to Earth

Solar flares are often accompanied by massive plasma ejections called coronary mass ejections, or CMEs. When large amounts of high-energy particles from CMEs hit the Earth, they generate radioactive material that is sealed in the geologic record.

This has allowed scientists to identify at least five extreme solar particle superflare events from the sun during Earth’s history. Three of these have occurred in the last 12,000 years, with the most violent appearing to have hit our planet in 775 AD.

However, it is not entirely clear how often superflares are associated with CMEs. This means that they may not always make their mark in the Earth’s geologic record and may therefore be underestimated. It also means that the effects of superflares on Earth are not entirely predictable.

“The effect of superflares on Earth? That’s a good question. There are various aspects to consider,” Vasilyev said. “What is the potential impact on technology systems? How do these events affect the biosphere? There are a lot of interesting questions to answer.”

An illustration of lightning bursting from the poles of a sun-like star missing an Earth-like planet

An illustration of superflares erupting from the poles of a sun-like star, missing an Earth-like planet. (Image credit: Leibniz Institute for Astrophysics Potsdam/J. Fohlmeister)

Research in 2018 by a separate team of scientists suggested that a superflare from the sun could have catastrophic effects on Earth’s atmosphere and therefore life.

However, in 2021, another research team found that superflares tend to erupt from near the poles of stars, meaning that if the sun were to erupt in such a flare, there’s a good chance it would miss Earth.

“I hope this study will motivate other researchers to investigate the potential impacts of such extremes space weather the events in more detail,” Vasilyev continued.

While the potential impact of a superflare event on Earth remains somewhat unclear, what is evident from this research is the need for caution.

“The new data are a stark reminder that even the most extreme solar events are part of the sun’s natural repertoire,” said team member Natalie Krivova, also of the Max Planck Institute for Solar System Research.

The team will now continue their research into explosions from other stars and the potential effects of such an event closer to home.

“There are several directions we are following,” Vasilyev said. “For example, we investigate the impact of such events on Earth’s atmosphere and technological systems, understand the link between superflares and extreme solar particle events, and determine the conditions necessary to produce such superflares.”