Sun Unleashes 17 Powerful Flares in One Day, Including Rare X8.11 Event

On February 1, scientists recorded 17 solar flares of M-class and higher, making it the second-highest number of such events observed in a single day over the past decade. The record-holder remains December 29, 2024, according to the Solar Astronomy Laboratory of the Space Research Institute of the Russian Academy of Sciences.

Rare X-Class Flare Detected

The peak of solar radiation occurred the following day, February 2, at 02:57 Moscow time. Scientists registered an extremely powerful X8.11-class flare, one of the strongest events of the current solar cycle.

Experts stressed that the flare poses no direct threat to Earth, although the possibility of indirect effects remains under assessment.

"At the moment of the explosion, the active region was located at an angle of about 35 degrees from the Sun-Earth line. Direct impacts on the planet from such positions are completely ruled out. As for tangential effects, the situation will become clearer in a few hours. At this stage, nothing is clear at all,” the laboratory said.

The X8.11 flare ranked as the third most powerful event of the current 25th solar cycle, which reflects periodic changes in the Sun's magnetic activity and lasts an average of 11 years.

Unexpected Reversal After Solar Calm

Just one day earlier, researchers reported a strong M6.6-class flare, noting that the Sun had appeared to enter a prolonged period of reduced activity.

"By all indications, the Sun was entering a deep depression lasting a month or longer. During the final week of January, sunspots and coronal holes nearly disappeared, X-ray radiation flows dropped five to six times compared to mid-month, and the overall activity index fell to around 1 out of 10,” researchers at the Space Research Institute said.

The sudden surge in powerful flares therefore came as a surprise, reversing expectations of an extended lull in solar activity.

How Solar Flares Are Classified

Solar flares are classified according to the intensity of their X-ray radiation: A, B, C, M, and X, from weakest to strongest. A-class flares correspond to radiation levels of 10 nanowatts per square meter at Earth's orbit, with each subsequent class representing a tenfold increase in power.

• A-class flares are the weakest and have no noticeable impact on Earth.
• B-class flares are minor events barely distinguishable from background solar radiation.
• C-class flares remain relatively weak and cause no significant effects on the planet.
• M-class flares represent medium-strength events that can trigger brief radio interference in polar regions and minor radiation storms, posing risks to astronauts.
• X-class flares are the most powerful and can cause prolonged radiation storms capable of disrupting satellites, communication systems, and even ground-based technologies and power grids.