Sun's largest sunspots may have potential to trigger superflares

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: The sun is capable of great things. In massive eruptions, it repeatedly hurls particles and radiation into space.

This solar bombardment can be dangerous for technical infrastructure on Earth: For example, satellites and transformers in substations can be damaged. The sun offered an impressive demonstration of its strength in 1859. The solar storm that struck Earth during the so-called Carrington Event was so powerful that auroras were visible as far as the Caribbean, and sparks flew from the receivers in telegraph offices.

But can the sun accomplish even more? Can it rage even more violently and generate so-called superflares? These are bursts of radiation that release more energy than trillions of hydrogen bombs and have so far been observed directly only on distant stars.

Researchers at the Max Planck Institute for Solar System Research (MPS) in Germany and the University of Colorado in the U.S. explore this question in their latest paper, published in the journal Philosophical Transactions of the Royal Society A, and find further evidence of our star's eruptive skills. The amount of energy the sun releases during a flare can be measured directly only outside Earth's atmosphere or determined indirectly from data and images from space probes. Both have been possible only since the beginning of the space age about 70 years ago.

There has been no superflare since then. But this period is merely the blink of an eye in the life of our 4.6-billion-year-old star. "There is some evidence to suggest that the sun, too, can produce superflares at great intervals.

However, there is no direct proof," explained MPS scientist Natalie Krivova, lead author of the new study. Such clues can be found, for example, by looking at the sun's peer group, which comprises many thousands of stars. In late 2024, researchers at the MPS were able to show that superflares occur about once a century on stars that resemble the sun in key characteristics.