Superflares are some of the most brilliant pyrotechnic displays in the galaxy. They are massive bursts of energy ejected from the surface of a star.
Why stars eject these huge bursts of energy is still puzzles scientists.
Astronomers previously thought these explosions occurred mostly on stars that, unlike our Sun, were young and active.
But now a new study suggests that superflares can also occur on older, quieter stars like earth – however once in a millennium.
“Our study shows that superflares are rare events. But there is some possibility that we could experience such an event in the next 100 years or so,” said Yuta Notsu, the lead author of the study and a visiting researcher at CU Boulder.
“Normal-sized flares are common on the sun. But what the Kepler data was showing seemed to be much bigger, on the order of hundreds to thousands of times more powerful than the largest flare ever recorded with modern instruments on Earth.”
“When our sun was young, it was very active because it rotated very fast and probably generated more powerful flares. But we didn’t know if such large flares occur on the modern sun with very low frequency.”
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If a superflare erupted from the sun, he said, Earth would likely sit in the path of a wave of high-energy radiation. Such a blast could disrupt electronics across the globe, causing widespread blackouts and shorting out communication satellites in orbit.
To make the new discovery, astronomers observed data from the European Space Agency’s Gaia spacecraft and from the Apache Point Observatory in New Mexico.
Over a series of studies, the group used those instruments to narrow down a list of superflares that had come from 43 stars that resembled our sun. The researchers then subjected those rare events to a rigorous statistical analysis.
From quantifications, scientists found that younger stars tend to produce the most superflares, generating them once in a week.
Notsu said, “If a superflare occurred 1,000 years ago, it was probably no big problem. People may have seen a large aurora. Now, it’s a much bigger problem because of our electronics.”
So, the results of the study should definitely be a wake-up call for life on our planet.
The researchers published their results in May in The Astrophysical Journal.