The Sun is putting on quite a show right now. Earth-facing sunspot region 4366 has been erupting almost non-stop since it emerged on January 30, producing six X-class solar flares so far.
The latest, an X4.2 flare, occurred just after 7 a.m. ET on Wednesday. These sudden eruptions of electromagnetic radiation are ranked according to their strength using a classification system of five categories—A, B, C, M, and X—with A being the weakest and X the strongest. Similar to the Richter scale for earthquakes, each letter represents a ten-fold increase in energy output.
Within each letter class, there is a numerical scale ranging from 1 to 9 that space weather forecasters use to rank a flare’s peak intensity, with 9 being the strongest. X-class flares, however, can far exceed this scale. Sunspot region 4366 produced the most powerful flare of 2026 on Monday, unleashing an X8.1 and associated coronal mass ejection (CME)—a massive explosion of plasma and magnetic field from the Sun’s outer atmosphere.
An impulsive X4.2 flare occurred at 04/1213 UTC from Region 4366. No CME signatures have been identified in imagery at this time. Stay tuned for updates. pic.twitter.com/YDc2UHmeAA
— NOAA Space Weather Prediction Center (@NWSSWPC) February 4, 2026
Geomagnetic storm in the forecast?
Scientists at NOAA’s Space Weather Prediction Center (SWPC) are tracking this CME as it hurtles toward our planet. When these eruptions impact Earth’s magnetosphere, the influx of charged particles can produce dazzling aurora and geomagnetic storms. When intense enough, these storms can disrupt or damage power grids, satellites, and radio communications.
Models suggest the bulk of solar material from this CME will pass by Earth on Thursday evening, though the magnetosphere could still receive a glancing blow, the SWPC said Monday. As such, the agency has issued a G1 (minor) geomagnetic storm watch through Friday, but such a low-intensity storm is unlikely to have a significant impact on technology or infrastructure.
The X-class flare associated with this CME, however, already caused some widespread issues. Strong R3 radio blackouts were documented across parts of the South Pacific, with shortwave radio disruptions reported across eastern Australia and New Zealand, Space.com reported.
Wednesday morning’s X4.2 flare might also have triggered disruptions or total loss of high-frequency radio signals on the Sun-facing side of Earth. SWPC models show that this flare raised the risk of radio blackouts across the Atlantic, primarily over the western coast of Africa, though disruptions have not yet been reported.
Why is this sunspot region so active?
Sunspot region 4366 is visible in the top-center portion of this image taken by Gizmodo Science Editor George Dvorsky on Wednesday, February 4, 2026 © George DvorskySpaceweather.com describes sunspots as “magnetic islands” on the Sun. Their intense magnetism—caused by localized concentrations of magnetic field lines—is what drives these spots to produce solar flares and CMEs.
By this definition, sunspot region 4366 is like a gigantic archipelago—a chain of magnetic islands stretching more than 200,000 miles (322,000 kilometers) across the surface of our home star. It rapidly grew to this scale over the past several days, and its recent activity has made it one of the most flare-productive regions of Solar Cycle 25.
The Sun is at the peak of its current solar cycle, which explains why it’s been exceptionally active over the past year. This period—known as solar maximum—is associated with a greater number of sunspots and therefore a higher frequency of solar flares and CMEs. For astronomers, this creates more opportunities to observe the incredibly dynamic behavior of our home star.
They will certainly be keeping an eye on sunspot region 4366 while it remains visible, as this flare factory doesn’t appear to be slowing down anytime soon.
English (US) ·