Sun unleashes strongest solar flare of 2025, sparking radio blackouts across Africa and Europe

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The X5.1-class eruption from sunspot AR4274 is this year's most powerful solar flare and Earth is in the firing line.

close up view of the sun firing off a colossal X5.1 solar flare on Nov. 11.
The X5.1-class eruption from sunspot AR4274 marks this year's most powerful solar flare and Earth is in the firing line. (Image credit: NOAA Space Weather Prediction Center)

Check out the ripples from the coronal wave lifting off during the X5.1 solar flare. (Image credit: NOAA Space Weather Prediction Center)

The sun erupted in spectacular fashion this morning (Nov. 11), unleashing a major X5.1-class solar flare, the strongest of 2025 so far and the most intense since October 2024.

This outburst is the latest in a series of intense flares from AR4274, which also produced an X1.7 flare on Nov. 9 and an X1.2 on Nov. 10. Those flares were accompanied by coronal mass ejections (CMEs) that could combine and impact Earth overnight tonight, possibly triggering strong (G3) geomagnetic storm conditions and widespread auroras, according to NOAA's Space Weather Prediction Center. While analysis of today's eruption is ongoing, scientists are monitoring coronagraph data to determine whether the X5.1 launched a CME directly toward Earth. With AR4274 in an Earth-facing position, any associated outburst is likely to be heading for us.

Coronagraph imagery shows the CME lifting off in rapid fashion this morning (Nov.11) (Image credit: NOAA Space Weather Prediction Center)

Solar flares are ranked by strength in five classes, A, B, C, M and X, with each step representing a tenfold increase in energy output. X-class solar flares are the most powerful kind and the number following the X describes the flare's intensity. At X5.1, this latest eruption sits toward the top of the scale.

The eruption sent a surge of X-rays and extreme ultraviolet radiation toward Earth, ionizing the upper atmosphere and causing widespread radio signal degradation. Strong (R3) radio blackouts were recorded over Africa and Europe.

Radio blackouts associated with the X5.1 solar flare on Nov. 11. (Image credit: NOAA Space Weather Prediction Center)

This active region has become one of the most prolific solar flare producers of Solar Cycle 25, marking a fiery peak in what's already been an extraordinary week for solar activity.

This is a developing story and will be updated later today as more data on the flare and associated CME becomes available.

Daisy Dobrijevic
Daisy Dobrijevic
Reference Editor

Daisy Dobrijevic joined Space.com in February 2022 having previously worked for our sister publication All About Space magazine as a staff writer. Before joining us, Daisy completed an editorial internship with the BBC Sky at Night Magazine and worked at the National Space Centre in Leicester, U.K., where she enjoyed communicating space science to the public. In 2021, Daisy completed a PhD in plant physiology and also holds a Master's in Environmental Science, she is currently based in Nottingham, U.K. Daisy is passionate about all things space, with a penchant for solar activity and space weather. She has a strong interest in astrotourism and loves nothing more than a good northern lights chase!

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