Astronomers may have seen for the first time how the Sun gives signals about an approaching powerful flare long before it occurs. An analysis of data collected before one of the strongest flares of 2024 revealed a series of unusual processes in the solar atmosphere that could become the key to more accurate space weather forecasts.

This is reported in a new study published in the journal Solar Physics.

A rare observational stroke of luck

According to Space.com, on October 3, 2024, the Sun produced a powerful X9-class flare. Fortunately, several hours before it, NASA's IRIS (Interface Region Imaging Spectrograph) spacecraft was already conducting high-detail observations of the active region. This made it possible to obtain nearly five hours of continuous data before the explosion — an extremely rare and valuable set of observations.

The lead author of the study, Louis Seyfritz from the New Jersey Institute of Technology, explained that he had chosen this event because he expected the flare to be powerful enough to reveal precursors, adding that such strong flares are very few.

What happened before the flare

The analysis showed that approximately three hours before the flare, noticeable changes began in the solar atmosphere:

  • Plasma brightness increased
  • Turbulence (non-thermal velocity) grew
  • Regular oscillations with periods of 7–10 minutes and 18–21 minutes appeared

These oscillations were concentrated in the zone where magnetic fields of opposite polarity meet — precisely where tension typically builds up before major flares.

About 15–20 minutes before the explosion, turbulence sharply intensified, and plasma began moving outward. This could be a sign that accumulated magnetic energy had started to be released.

Seyfritz noted that if such oscillations are observed before a flare, it could be a strong indicator that a flare is about to occur.

Prospects for forecasting

For now, this is just one event, and scientists do not yet know whether these signs will repeat before other powerful flares. Confirmation will require analysis of a much larger number of cases. However, the results open up the prospect of creating an early warning system for solar storms.

The researcher emphasized that this is precisely what they are aiming for.

In brief

For the first time, scientists have recorded systematic changes in the Sun's atmosphere several hours before a powerful X9 flare. About three hours before the explosion, plasma brightness and turbulence increased, and characteristic oscillations appeared. These signs could become the basis for improving space weather forecasts. The study was published in the journal Solar Physics.