
Sun activity for September 26, 2023: Geomagnetic storm expected. More red auroras?
Today’s top news: A G1 (minor) geomagnetic storm is ongoing at the time of this writing, with more stormy conditions anticipated through the rest of the day. The G1 threshold was reached at 8:09 UTC this morning. With Earth’s magnetic field still feeling the effects of Sunday’s coronal mass ejection (CME) arrival, NOAA forecasters have issued an alert for auroral displays. Keep an eye out for more red auroras! And don’t forget to share your beautiful aurora photos with us.
Last 24 hours: Sun activity is back to low, but we saw filament eruptions all over the solar disk, particularly in the northeast and northwest. These filaments hurled ejecta into space, and we await the results of specialist analysis to determine if a component of those blasts is coming our way. Over the past day (11 UTC yesterday to 11 UTC today), only C class flares were produced – 18 in total. The largest was a C5.7 from the small but mighty sunspot region AR3445 at 4:28 UTC on September 26. AR3445 also became the lead flare producer of the past day, with ten of the 18 flares. AR3435 and AR3445 currently hold the potential for large flares, as they both show a delta magnetic complexity. The sun has nine numbered sunspot regions today, including two new kids in the neighborhood: AR3447 and AR3448.
Next 24 hours: Today’s forecast is a 99% chance for C flares, a 40% chance for M flares, and a 15% chance for X flares.
Next expected CME: No Earth-directed CMEs were observed in the available imagery.
Current geomagnetic activity: The Earth’s magnetic field is active with a G1 (minor) geomagnetic storm ongoing at the time of this writing (11 UTC on September 26). More G1 storms are expected today as the effects from Sunday’s CME arrival continue. Quiet to unsettled levels are expected tomorrow.



What a show… Breathtaking substorm at ca 1 am local time near Rostock. Reds visible to the eye.
#Polarlicht_Rostock #aurora #nordlichter @treetanner @NightLights_AM @meteoHRO #rostock #Auroraborealis @Nordkurier pic.twitter.com/DmNMtH4w97
— Christian Hering-Junghans (@C_HJunghans) September 25, 2023
Sun activity for September 25, 2023: Surprise strong CME brings rare red aurora
What fun! Earth experienced a coronal mass ejection (CME) impact late yesterday (September 24, 2023). We’d expected a geomagnetic storm, but not a G3 (strong) storm. But G3 it was! And many in Europe and northernmost North America were surprised with the sight of a rare red aurora. In the aurora, red is created by oxygen in Earth’s atmosphere. This color is one of the more difficult ones to detect with the unaided eye because the human eye is less sensitive to red light. Many past reports of red auroras were associated with extreme magnetic storms. Last night’s storm wasn’t extreme, although it was strong. Why did people see this rare red aurora? We don’t know. But scientists will surely be looking today, trying to understand the conditions that led to these beautiful displays.
Last 24 hours: Over the past day (11 UTC yesterday to 11 UTC today), sun activity was moderate, due to a single M flare. In all, the sun released 18 flares, 13 of which came from yesterday’s hero, AR3445. This sunspot region – though small in size – is turning out to be the little engine that could! But AR3445 didn’t produce the largest flare of the past day. That was an M1 flare from AR3443 at 14:51 UTC on September 24, 2023. The M flare caused an R1 (minor) radio blackout over South America. AR3435 and AR3445 both show some magnetic complexity, with a delta region. The sun currently has nine numbered sunspot regions.
#Aurora #Auroraborealis #Northernlights #Polarlights #Polarlichter
For a few minutes it suddenly exploded and even here at roughly 54N it looked like you’re in the polar areas. All the movement was visible, all the colors, im freaking out ????? this was so awesome (ALT-txt) pic.twitter.com/Y0WHd5ZFGz
— Darth thromBOOzyt? (@krasmanalderey) September 24, 2023
Northern lights from the Moray coastal trail, Scotland ???????
•
25/9/23
•#scotland #moray #moraycoast #morayfirth #findhorn #forres #scottishhighlands #northernlights #auroraborealis #astrophotography #StormHour #ThePhotoHour @TamithaSkov pic.twitter.com/UCRcuMRLaI— Moray Firth Photo ??????? (@morayfirthphoto) September 25, 2023
Here we go! Aurora live Alaska! @TamithaSkov pic.twitter.com/rqYeVUoifg
— ?Angel Brise’ Alaska Adventurer? (@AngelBrise1) September 25, 2023
#Aurora from Penryn Cornwall!! About as far south as you can get in the UK and still visible#Cornwall #Auroraborealis pic.twitter.com/1sXlqRfRjR
— Christopher Probert (@tophe_probert) September 24, 2023

Sun activity for September 24, 2023: Meet sunspot region AR3445 (again)
We have a new kid in town! Well, not new exactly. Sunspot region AR3445 rotated onto the Earth-facing disk of our star a few days ago. It gained a delta region (a possible indication of strong flaring), and it produced a two big flares. Then it went away. Now it has came back! And now it has kicked into high gear and produced a lot of flaring. It produced 15 of the 21 solar flares of the past day. That’s including three of the past day’s four M flares, plus the largest event of the period, an M4.4. AR3445 is far from being the biggest spot region on the sun. It’s little, but mighty! And there’s more news. We might see more auroral activity into the coming week, due to the influence of a coronal hole and the possible arrival of CMEs today and September 26. Read more below, and stay tuned!
Last 24 hours: Sun activity continues at a moderate levels thanks to four M flares during the past day (11 UTC yesterday to 11 UTC today). The sun released a total of 21 flares, 15 of which came from AR3445. This region produced the largest event, an M4.4 flare and two of the other M flares. Each M flare caused an R1 (minor) radio blackout. The breakdown of the M flares and R1 blackouts of the period is:
– M1.6 by AR3446 at 20:14 UTC on September 23. R1 (minor) radio blackout over the Pacific.
– M1.2 by AR3445 at 02:51 UTC on September 24. R1 (minor) radio blackout over Australia.
– M1.9 by AR3445 at 03:09 UTC on September 24. R1 (minor) radio blackout over Australia.
– M4.4 by AR3445 at 03:17 UTC on September 24. The largest of the four, it produced an R1 (minor) radio blackout over Australia.
By the way, the M4.4 was a long-duration event, though it appeared more as a set of smaller flares combined together rather than a single long event. If, like many long duration events, it produced a coronal mass ejection (CME), the region’s position makes it ideal for sending that CME towards us. We await further analysis to know the final outcome. In the meantime, also in the past day, AR3443 gained a delta region. And AR3441 now has a slightly less complex, beta-gamma, magnetic configuration. None of the regions are particularly large, so we’ll see what happens next. The sun currently has 11 numbered sunspot regions.


The sun in recent days







Sun images from our community
We invite you all to send us your beautiful recent photos of sunspots and auroras. Naturally, we love receiving your photos! And to those of you who’ve already posted a photo to our community page, thank you.





Bottom line: Sun activity for September 26 is low, with C flares only. The recent CME impact continues to provoke geomagnetic storming. More auroras could be on the way!