Sun news: Farewell prolific sunspot region AR4168!

Sun news August 12: Farewell prolific sunspot region AR4168!

(11 UTC to 11 UTC)

Today’s top story: AR4168, the sunspot region behind much of the elevated solar activity in recent weeks, has now rotated out of view over the sun’s western horizon. It left with a bang, firing off five M (moderate) and 14 Cs (common) flares in the past 24 hours. And we’ve been observing jets and prominences on the western limb (edge) as AR4168 continues its prolific activity out of view. In fact, today’s largest flare – an M1.8 from this region – was likely even larger in reality, as the horizon blocked most of our view of this blast. Farewell AR4168!

• Flare number: AR4168 was by far the most productive region over the past day, stealing the show with five moderate flares plus another 14 C flares. The largest event was an M1.8 at 1:23 UTC on August 12. It provoked an R1 (minor) radio blackout that affected an area over the Philippine Sea. The sun produced a total of 22 flares: five Ms plus 17 Cs.
• Sunspot regions: The sun now has eight active regions on its Earth-viewed side. AR4172 has retained its beta-gamma configuration, while the rest of the regions are small and magnetically simple. There is a newcomer on the solar disk: AR4179, in the southeast.
• Blasts from the sun? No Earth-directed coronal mass ejections (CMEs) were observed in available coronagraph imagery over the past day.
• Solar wind: The coronal hole high-speed solar wind stream remains in force, with speeds averaging around 570 km/s during the period. It’s up to 602 km/s at the time of this writing (11 UTC on August 12). The interplanetary magnetic field (IMF) stayed weak, with the Bz component also weak, intermittently alternating between southward and northward. It is southward at the time of this writing. A southward Bz is more favorable for auroras.
• Earth’s magnetic field: Conditions were mostly unsettled to active during the past day (Kp = 2-4).

What’s ahead? Sun-Earth forecast

• Flare activity forecast: Chances for moderate (M-class) flares are 55%, with a 10% chance for strong (X-class) events.
• Geomagnetic activity forecast:
  • Aug 12-13: Unsettled-to-active levels expected, with a chance of isolated G1 (minor) storms from ongoing high-speed stream effects.
  • Aug 14: Unsettled-to-active levels expected, but chances for G1 storms slowly decreasing as the solar wind weakens.

Sun news August 11: New view of a colossal solar blast

(11 UTC to 11 UTC)

The impressive geomagnetic storming we saw through the weekend has come to an end, with only a slight chance for short-lived G1 (minor) storms today. But, as history has shown us, you can’t rule out the sun to suddenly bring more action. Today, we’re looking back at one of the most noteworthy bursts of solar activity ever recorded: the solar storm of July 2012. NASA has released a new visualization of this storm (above), which consisted of 5 bursts of sun-stuff, or coronal mass ejections (CMEs). The largest of these was powerful enough to potentially disrupt power grids and satellite networks, leading scientists classify it in the same bracket as the Carrington Event of 1859, which was the strongest geomagnetic storm ever recorded. Thankfully, this huge 2012 CME didn’t reach Earth. But it did reach our sun-observing satellite STEREO-A, as you can see above. This CME benefitted from the 4 smaller CMEs that came before it, which cleared away the interplanetary material – largely dust, gas and plasma – in its path, letting it travel through space unusually quickly. And the most hair-raising part about this colossal event? Had it occurred just 9 days earlier, the rotation of the sun means that the CME would have headed straight for Earth!

• Flare number: Sunspot region AR4168 continues to dominate flare production with four moderate (M-class) events over the past day, despite showing signs of decay as it nears the sun’s western edge. The largest flare was an M2.3 at 15:07 UTC on August 10. This produced a CME, but analysis indicates it was not Earth-directed.
• Sunspot regions: Eleven regions are visible today. AR4168 remains the most prolific flare producer, though its magnetic details are now harder to assess as it moves off the visible solar disk. Growth has been observed in AR4172 (beta-gamma), AR4178 (beta) and AR4174 (beta) over the last day. A new active region is rotating into view on the southeast limb. The rest of the regions are small and magnetically simple.
• Blasts from the sun? Several coronal mass ejections (CMEs) occurred in the last day, but none appear to be Earth-directed.
• Solar wind: The coronal hole high-speed solar wind stream remains in force, with speeds holding between 550–580 km/s and trending slightly lower. The interplanetary magnetic field (IMF) stayed weak, with the Bz component also weak, occasionally dipping southward. A southward Bz is more favorable for auroras.
• Earth’s magnetic field: Conditions were mostly unsettled to active, with occasional G1 (minor) geomagnetic storm intervals (Kp 5) during the past day.

Sun news August 10: Storm easing, but auroras still possible

(11 UTC to 11 UTC)

Last night’s geomagnetic storm peaked at G2 (moderate) levels in the late afternoon UTC on August 9, fueled by the one-two punch of a coronal mass ejection (CME) from August 5 and a coronal hole high-speed stream. While conditions have eased, G1 (minor) storms are still possible today as the fast wind continues to buffet Earth’s magnetic field. The big question for aurora chasers: Will the fading storm still light up the skies tonight? There’s a decent chance, especially at higher latitudes, even with lingering moonlight from the August 8–9 full moon. Yes, you can still see auroras with a full moon!

• Flare number: Solar activity stayed at moderate levels thanks to three more M-class M-class bursts from powerhouse region AR4168. This time it was an M1.7 flare at 16:40 UTC on August 9, producing an R1 (minor) radio blackout. The largest event spot also contianed another M1.7 from AR4168 at 3:12 UTC on August 10, 2025. It created an R1 (minor) radio blackout. AR4168, now rotating toward the western limb, is showing signs of decay but remains the most active player. No Earth-directed CMEs were detected in the past day.
• Sunspot regions: Ten regions are visible today, with AR4178 newly numbered. AR4168 (beta-gamma) is still the largest but is losing intermediate spots. AR4172 in the northeast is slowly expanding. The rest are small and magnetically simple.
• Blasts from the sun? Several CMEs were spotted on coronagraph imagery, but none have a significant Earth-directed component.
• Solar wind: Conditions reflect the ongoing influence of a positive polarity high-speed stream. Wind speed rose from ~450 km/s early on August 9 to ~600 km/s by the UTC day’s end. The interplanetary magnetic field (IMF) weakened from 16 nT to ~6 nT, while the Bz component was strongly southward before 15:30 UTC, then trended neutral.
• Earth’s magnetic field: Activity ranged from unsettled to storm levels, with G1 (minor) storms through much of the day and a G2 (moderate) interval from 15:00–18:00 UTC. The forecast calls for active to G1 levels today, with the chance of another brief G2.

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Bottom line: Sun news August 12, 2025. Farewell AR4168! The most productive flare producer of recent weeks has now rotated out of view over the western horizon.