Sun news: Surprise M flare heralds an old region’s return

Sun news August 23: Surprise M flare heralds an old region’s return

(11 UTC to 11 UTC)

Today’s top story: The sun unleashed a long-duration M flare at 18:51 UTC on August 22. It surprised everyone and pushed solar activity to moderate. The blast came from an incoming, still-unnumbered region just over the sun’s southeast horizon. The flare triggered an R1 (minor) radio blackout over the Pacific Ocean southwest of Mexico and produced a Type II radio emission. Evidence suggests this may be the return of an old, magnetically complex region that previously fueled fiery activity on the sun’s far side. We’ll keep watch, as it rotates into view and earns its new sunspot number.

• Flare activity: Sun activity jumped to moderate over the past day, with three flares. The largest was an M1.7 event from the southeast limb at 18:51 UTC, which caused the R1 radio blackout. AR4191 contributed two smaller C-class flares during the same period.
• Sunspot regions: Four active regions currently face Earth. AR4191 remains the largest, while the other visible regions show simple alpha or beta magnetic configurations and appear stable. The incoming southeast limb region might bring more complexity – and more flare potential on the sun’s Earth-facing side – once it rotates fully into view.
• Blasts from the sun? No Earth-directed coronal mass ejections (CMEs) left the sun in the past 24 hours.
• Solar wind: Solar wind slowed from 535 km/s (1,200,000 mph) late on August 21 to 459 km/s (1,030,000 mph) by the end of August 22. The interplanetary magnetic field weakened, with Bz mostly northward but showing some brief southward swings. Forecasters expect waning high-speed stream effects through August 22, with background-like conditions returning by August 23.
• Earth’s magnetic field: Geomagnetic activity stayed quiet to unsettled (Kp 1–3) on August 22. Forecasts call for similar conditions on August 23, with only a small chance of isolated active intervals or G1 (minor) geomagnetic storming if CME remnants graze Earth. Activity should settle further on August 24–25.

What’s ahead? Sun-Earth forecast

• Flare activity forecast: Expect mostly low levels through August 23. The chance for M-class flares increases to 15% on August 24 as the returning region rotates into view. The chance for an X-class flare remains very low (1%).
• Geomagnetic activity forecast:
  • Aug 23–24: Mostly quiet to unsettled as coronal hole effects fade.
  • Aug 25: Unsettled to active, with possible storm intervals as a new coronal hole high-speed stream arrives.
  • Aug 26: Activity continues at unsettled-to-active levels, then gradually declines.

Sun news August 22: This sun blast is headed for Mars

(11 UTC to 11 UTC)

At 8:24 UTC on August 21, the sun unleashed a dramatic coronal mass ejection (CME). Earthly coronagraphs recorded this blast of solar materials and magnetic fields as a wide, fast halo event. Halo events often indicate blasts headed Earth’s direction, but this one launched from the far side of the sun and is racing toward Mars. It’s expected to reach the red planet by August 25. Maybe some Mars spacecraft (rovers or orbiters) will record stirrings to the red world’s near-space environment.

• Flare activity: Sun activity remained at low levels, producing only weak C-class flares. The largest was a C2.3 from AR4191 at 15:56 UTC on August 21. This same active region was the lead flare producer of the past day. It produced six out of the seven flares of the day.
• Sunspot regions: Four sunspot regions now face Earth. AR4191 dominates as the largest, while AR4187 and AR4192 remain small and stable. Spots behind AR4191 may reveal more complexity as they rotate into view.
• Blasts from the sun? As mentioned above, a large CME erupted at 08:24 UTC on August 21, but coronagraphs showed it originated on the far side. No Earth-directed CMEs left the sun in the past 24-hours.
• Solar wind: Solar wind from the coronal hole declined during the day. Speeds dropped to 420-470 km/s (940,000-1,050,000 mph), then increased again near 535 km/s (1,200,000 mph) late in the period. The interplanetary magnetic field (IMF) strength weakened, with the Bz component mostly north-oriented with some southward variations to end the period north-oriented. A southward Bz component is more favorable for auroras. Forecasters expect waning high-speed stream effects through August 22, with a return to background-like conditions by August 23.
• Earth’s magnetic field: Geomagnetic activity stayed quiet to unsettled (Kp 1-3) on August 21. Forecasts call for the same on August 22, with a small chance of isolated active intervals or G1 (minor) geomagnetic storming if CME remnants brush Earth. Conditions should quiet down further by August 23–24.

Sun news August 21: Explosive activity in the northeast

(11 UTC to 11 UTC)

Shortly after the huge prominence eruption yesterday morning, a filament erupted in the northeast at around 11:00 UTC. The SOHO spacecraft’s LASCO C2 instrumented detected a burst of solar material – a coronal mass ejection, or CME – soaring out from this eruption at 11:24 UTC. Then at 8:30 UTC this morning, LASCO C2 recorded another huge blast of sunstuff. This eruption likely occurred on the far side of the sun, as we saw no flare that could be associated with this event on the Earth-facing side. Stay tuned to see if this explosive activity continues.

• Flare activity: Only three C class (common) flares were produced by our star over the past 24 hours, placing activity at low. The largest of the three flares was a C3.3 flare at 0:11 UTC on August 20 from AR4191 in the northeast.
• Sunspot regions: The sun has five labeled active regions on its Earth-facing side. All these regions are small and stable with simple alpha or beta configurations. There is a newcomer on the solar disk now numbered AR4191. Its classification can’t be confidently identified as it’s currently too close to the east limb (edge), but we can see that it’s larger than the rest of the sunspots on the solar disk. We will keep observing this region to see what it’s got in store. Meanwhile, a large coronal hole is forming in the solar northeast. We could soon be feeling the effects of its high-speed solar wind.
• Blasts from the sun? At around 11:24 UTC on August 20, SOHO’S LASCO C2 instrument observed a coronal mass ejection (CME) in the northeast. Due to its location on the very edge of the solar limb (edge), it’s not Earth-bound.
• Solar wind: Solar wind speeds dropped from 624 km/s yesterday to 497 km/s at the time of this writing. The interplanetary magnetic field remains at low levels. The Bz component has been mostly north-oriented during the period and remained northward at 10:00 UTC this morning. A southward Bz component is more favorable for auroras.
• Earth’s magnetic field: Conditions were quiet to unsettled (Kp = 1-3) over the past 24 hours, staying at Kp = 1 at the time of this writing.

Sun news August 20: Huge blast this morning!

(11 UTC to 11 UTC)

At 4:30 UTC this morning, a large prominence – a long rope of solar material and magnetic fields – erupted over the solar southeast horizon. And this blast sent a spectacular blast of sun-stuff into space. Since it was fired on or just behind the horizon, this coronal mass ejection (CME) is not on its way to trouble Earth’s magnetic field. But our planet has experienced G1 (minor) geomagnetic storming over the past day, thanks to a stream of high-speed solar wind from a coronal hole. And forecasters expect the storming to continue today, with a slight chance for G2 (moderate) storms if the anticipated glancing blow from a CME fired on Sunday adds to the disturbance. Stay tuned.

• Flare activity: Activity dropped down to low after only C and B-class (common and basic) flares were produced by our star over the past day. During the last 24 hours, the sun produced a total of five flares: three Cs and two B flares. The largest flare was a C2.5 at 2:39 UTC on August 20 from an incoming active region in the northeast. This as-yet-unnumbered active region was the lead (and only) flare producer of the day.
• Sunspot regions: Our star today has three numbered active regions on the side we see from Earth. These regions remain small and stable with simple alpha or beta configurations. There is a newcomer on the Earth-viewed solar disk: AR4189, now located in the northeast.
• Blasts from the sun? SOHO’S LASCO C2 instrument registered the coronal mass ejection from the huge filament eruption this morning. Due to its location on the very edge of the solar horizon, no component is Earth-bound. Other than that, no coronal mass ejections (CMEs) have been observed in available coronagraph imagery.
• Solar wind: Solar wind raised from speeds of 425 km/s yesterday to a peak of 760 km/s at 5:48 UTC on August 20, and sits at 624 km/s at the time of this writing. The interplanetary magnetic field is at low levels. The Bz component has been mostly south-oriented during the period. It moved south at 10:00 UTC this morning. A southward Bz component is more favorable for auroras.
• Earth’s magnetic field: Conditions were quiet to active (Kp = 2-5) over the past 24 hours, with a G1 (minor) geomagnetic storm level recorded at 18 UTC on August 19. Disturbance is sitting at Kp = 3 at the time of this writing.

Sun news August 19: Geomagnetic storms and auroras tonight?

(11 UTC to 11 UTC)

Earth’s magnetic field is calm right now, but conditions are shifting. A powerful knot of solar winds known as a corotating interaction region (CIR) is soon to reach Earth, followed by a stream of high-speed solar wind from a coronal hole. And to top it off, a blob of sun-stuff – a coronal mass ejection (CME) – fired on Sunday could give our magnetic field a glancing blow as early as this evening. These factors could combine to produce G1 (minor) geomagnetic storms tonight. And that means the potential for auroras at high latitudes!

• Flare activity: Activity jumped up to moderate over the past 24 hours thanks to an M-class (moderate) flare. During our observation period the sun produced a total of 10 flares: an M, six Cs (common) and three B (weak) flares. The largest flare was an M1.1 at 4:39 UTC on August 19 from AR4188. The blast caused an R1 (minor) radio blackout that affected an area over the South China Sea.
• Sunspot regions: Four numbered sunspot regions now face Earth. Most remain small and simple. A region near the center of the solar disk shows weak opposite polarity spots, hinting at slight complexity. There are two newcomers on the Earth-viewed solar disk: AR4187 and AR4188, both in the southeast.
• Blasts from the sun? Today’s M flare is still under analysis, but the initial review suggests solar stuff from this flare is not coming to us at Earth. Other than that, no coronal mass ejections (CMEs) have been observed in available coronagraph imagery.
• Solar wind: Solar wind raised from speeds of 320 km/s to peaks of 450 km/s, and sits at 425 km/s at the time of this writing. The interplanetary magnetic field is at moderate levels. The Bz component has been mostly north-oriented during the period, but moved south at 9:30 UTC this morning. A southward Bz component is more favorable for auroras. Conditions should change late today as the CIR and coronal hole high-speed stream arrive, possibly pushing speeds toward 600–700 km/s.
• Earth’s magnetic field: Conditions stayed quiet to unsettled (Kp = 2-3) over the past 24 hours, sitting at Kp = 2 at the time of this writing.

Sun news August 18: Storms brewing as fast solar wind arrives

(11 UTC to 11 UTC)

Earth’s geomagnetic environment is currently quiet, but disturbance is on the way. A complex knot of solar winds known as a co-rotating interaction region (CIR) is expected to reach Earth later today, followed by a stream of high-speed solar wind from a coronal hole. This will likely kick up geomagnetic activity, with G1 (minor) geomagnetic storms likely tomorrow and possibly extending into August 20. Plus, a coronal mass ejection (CME) fired yesterday morning may add to this disturbance if it grazes Earth late tomorrow or early on August 20. Aurora hunters at high latitudes, get ready!

• Flare activity: Activity stayed low over the past 24 hours, with 12 small C-class flares and one B9.0 (moderate) flare. Region AR4180 produced the largest flare, a C3.3, at 19:58 UTC on August 17.
• Sunspot regions: Four numbered sunspot regions now face Earth. Most remain small and simple. A region near the center of the solar disk shows weak opposite polarity spots, hinting at slight complexity. AR4172 continues to depart over the western limb (edge). A new region is rotating in from the southeast limb.
• Blasts from the sun? Coronagraph imagery revealed a coronal mass ejection (CME) at 10:24 UTC yesterday. Analysis suggests the CME may graze Earth late on August 19 or early August 20. Any other CMEs over the past day were fired away from Earth.
• Solar wind: Solar wind stayed calm over the past day, with speeds of 300–350 km/s and weak magnetic fields. The Bz component never turned southward for long. A southward bz component is more favorable for auroras. Conditions should change late August 18 as the CIR and coronal hole high-speed stream arrive, possibly pushing speeds toward 600–700 km/s.
• Earth’s magnetic field: Conditions stayed quiet (Kp = 0–2) over the past 24 hours. Activity should remain low through much of today, then rise to unsettled or active late in the day, with the chance for geomagnetic storms peaking on August 19.

The sun in recent days

Earlier sun images

Sun images from our community

We sometimes feature sun images obtained using hydrogen-alpha filters. Read why.

Submit photos here.

View community photos here.

Bottom line: Sun news August 23, 2025. The sun fired off a surprise M-class flare over its southeast limb, hinting that an old active region is making a dramatic return.