Five Times More Flares Before the Storm express
The Sun has regions that resemble an overheated boiler: magnetic fields there twist into tight ropes and store energy. Every so often, a rope snaps, and a flare erupts, a powerful explosion that hurls streams of charged particles into space. Such blasts can knock out satellites and disrupt communications on Earth.
Scientists have devised a way to anticipate where a rope is about to break. They monitor small, bright ultraviolet flashes — visible only to specialized telescopes and lasting from a minute to an hour. It turns out that in regions where a major eruption will occur within hours, these flashes are five times more frequent than in quiet areas. It's as if light bulbs started flickering frequently in one neighborhood before an earthquake.
So far, the method has been tested on two regions of the Sun: one produced a powerful flare, the other remained quiet. The result is encouraging: in the hours before the eruption, the number of small flares rises sharply. If confirmed with more observations, space weather forecasts could become more accurate, and satellites and power grids on Earth would be safer.
Original abstract
as written by the authors arXiv:2604.26036
This study investigates the relationship between extreme ultraviolet (EUV) transient brightenings (TBs) and the onset of GOES X-class solar flares in active regions (ARs). We introduce the Brightenings AnD Polarity Inversion Tracking (BADPIT) method that detects TBs across multiple SDO/AIA channels. To identify TBs, we impose two independent thresholds: a 3-(sigma) intensity-based criterion and a power-law divergence approach. We apply the BADPIT method to datasets of a flaring and a non-flaring AR for 24 hours as a pathfinder to a comprehensive statistical study for a complete performance verification: the flare-productive AR 11429 and the quiescent AR 13186, both sharing a similar Hale sunspot classification. Preliminary results are encouraging: significantly more TBs are detected in the flaring AR, with up to five times more 3-(sigma) thresholded TBs, while power-law thresholded events were frequent only in the flaring AR and mostly absent in the non-flaring AR. We find that both the power-law threshold method and the 3-(sigma) method can be useful diagnostic tools for distinguishing between imminent flaring or not, several hours before the onset of major solar flares.
The small flares that precede a big one last only a few minutes, but their combined energy is comparable to millions of atomic bombs.
In the movie Knowing, solar flares wipe out all life on Earth — an early warning could have given humanity a chance to take shelter.