
Sun news October 12: Sun-stuff and solar wind on the way
Today’s top story: A fast blob of sun-stuff — a coronal mass ejection (CME) — could give Earth a glancing blow later today. The sun fired this CME our way during an M6.4 (moderate) flare on Saturday. If it does reach us, it could add to the effects of high-speed solar wind currently streaming to us from a coronal hole. Together, these effects could disturb our magnetic field to G1 (minor) geomagnetic storm levels. In fact, the U.K. Met Office sees a chance of G2 (moderate) or even G3 (strong) levels. Aurora-watchers across the northern U.K, northern U.S. states, southern New Zealand and similar geomagnetic latitudes should stay alert!
Past 24 hours on the sun
(11 UTC October 11 – 11 UTC October 12)
Flare activity: Solar activity stayed at low levels. Observers recorded 8 flares during the period: 6 C-class (common) and 2 B-class (weak).
- Strongest flare: A C1.2 from AR4545, peaking at 17:01 UTC on October 11.
- Other notable flares: AR4549 contributed a C1.1, peaking at 22:37 UTC on October 11.
- Lead flare producer: AR4545 led the list with three C-class flares.
Sunspot regions: Five numbered sunspot regions populated the visible disk, including one newcomer. A sixth, AR4552, decayed to plage.
- AR4549 (beta-delta): This region remained the most magnetically complex on the disk. However, it’s getting very close to the western horizon, which is making classification increasingly difficult. It produced only one minor C flare during the period. Still, forecasters consider it the main source of possible M-class and X-class (strong) flares in the days ahead.
- AR4545 (beta): This region saw new magnetic field emergence during the period. It was also the most prolific flare producer, firing the strongest flare (C1.2) plus two other C-class events. Even so, analysts noted overall decay in the region.
- AR4551 (beta-gamma): This region grew in both size and magnetic complexity. It’s now the largest region on the disk. Despite that growth, it stayed mostly quiet, producing only B-class flares during this window.
Blasts from the sun? Observers detected no new Earth-directed CMEs during the past 24 hours. However, the October 10 CME from AR4549’s M6.4 flare remains of interest.
Past 24 hours in space weather
Solar wind: Solar wind steadily decreased to a little above normal, reflecting the fading effects of the October 10 CME arrivals.
Bt, Bz and magnetic coupling: The total interplanetary magnetic field (Bt) started strong and slowly decreased to moderate, before dropping sharply to near-normal levels. The Bz component pointed northward throughout, limiting geomagnetic coupling.
Earth’s magnetic field: The geomagnetic field started the period at active levels (Kp 4). Conditions then eased to quiet as CME effects waned.
What’s ahead? Sun–Earth forecast
Flare activity forecast: Forecasters expect solar activity to stay at low levels overall. Even so, M-class flares remain likely, at 55% to 65% chance through October 13, mostly thanks to AR4549. A slight chance of X-class flares exists in the same window. By October 14, the M-class probability should drop to about 45% as AR4549 leaves the disk.
Geomagnetic activity forecast:
- October 12: Expect quiet-to-unsettled conditions early (Kp 2-3), rising to active levels later in the day. A G1 (minor) storm (Kp 5) is likely as the glancing October 10 CME and the coronal hole high-speed stream arrive together.
- October 13: Expect mostly active conditions, with isolated G1 (minor) storming likely as the coronal hole stream persists. The chance of G1 storms (Kp 5) gradually drops, with a slight chance of G2 (moderate, Kp 6). Note that this coronal hole has a negative polarity, which tends to be less effective at stirring geomagnetic storms at this time of year.
- October 14: Quiet to unsettled levels (Kp 2-3) should return as the coronal hole’s influence tapers off.
The sun in recent days

Earlier sun images

Sun images from our community

More sun images from our community

We sometimes feature sun images obtained using hydrogen-alpha filters. Read why.
Bottom line: Sun news, October 12, 2026: A blast of sun-stuff could reach Earth today. It could combine with a fast solar wind stream to trigger geomagnetic storms. Aurora watchers, stay alert!
