Three days after the Earth-facing side of the Sun showed no numbered sunspots, a newly emerged region near the center of the solar disk is developing the kind of tangled magnetic structure that forecasters associate with stronger flares. EarthSky's daily solar report, updated at 11:09 UTC (7:09 a.m. EDT) on Sept. 21, said sunspot region AR4534 had developed a beta-delta magnetic configuration and produced 9 of the 11 flares recorded over the prior 24 hours.

None of those flares was large. The strongest was a C3.7 that peaked at 22:34 UTC on Sept. 20 (6:34 p.m. EDT), a common, minor class of flare. Forecasters cited by EarthSky expect very low to low solar activity over the next three days, with only a slight chance of moderate M-class flares, mainly from AR4534.

The story is less about danger than about whiplash. A sun that looked like it was winding down now has a region worth watching, and it is doing so just as the September equinox opens the season when geomagnetic storms tend to be more frequent. For most people in the United States, the practical impact is limited to a possible aurora chance at high latitudes.

A Spotless Sun, Then a Fast-Developing Newcomer

On Sept. 18, the Earth-facing side of the Sun had no numbered sunspot regions, the first spotless day since Feb. 24, and Sept. 19 was a second spotless day in a row, according to EarthSky's daily sun news. Spotless days are a sign that the current 11-year cycle, Solar Cycle 25, is moving away from the maximum it reached in late 2024. For comparison, NOAA's Space Weather Prediction Center estimated 337 sunspots on Aug. 8, 2024, its highest single-day estimate since March 2001.

The quiet did not last. By Sept. 21, six numbered regions sat on the visible disk. AR4534, located near disk center, showed a proliferation of spots and a delta configuration forming in its northern intermediate portion. EarthSky's region notes described only minor growth in size but a rapidly developing, increasingly complex magnetic structure. A newcomer, AR4535, rotated into view in the northeast with a simple alpha magnetic layout.

A declining solar cycle is not a dormant one. Nature World News reported earlier this month that a solar region that had lost its sunspots still drove a rare proton burst, and significant eruptions remain possible in the years after solar maximum.

Reading the Delta Configuration

Sunspot groups are classified by how their magnetic fields are arranged. A simple alpha region has a single polarity. A beta region has both polarities clearly separated. A delta configuration packs opposite polarities tightly together, which can store magnetic stress that is released suddenly as a flare.

That is why forecasters pay attention when a delta appears. In its Sept. 21 report, EarthSky noted that the more magnetically complex a group becomes, "the greater the chance that it will fire off some big flares." Complexity raises the odds; it does not guarantee a major event, and many delta regions decay without producing one.

Location matters too. AR4534 sits near the center of the Earth-facing disk, a position from which a coronal mass ejection would be better aimed at Earth than one launched from the sun's edge. As of Sept. 21, analysts had detected no Earth-directed coronal mass ejections. The sun rotates about once every 27 days as seen from Earth, so AR4534 will remain on the Earth-facing side for roughly another week before moving toward the western limb.

Flares are ranked on a letter scale. C-class flares are common and minor. M-class flares are moderate and can cause brief R1 or R2 radio blackouts on the sunlit side of Earth, which mainly affect high-frequency radio used by aviation and amateur radio operators. X-class flares are the strongest.

Equinox Timing and a Split Storm Outlook

The September equinox occurs at 00:05 UTC on Sept. 23, which is 8:05 p.m. EDT on Sept. 22. Geomagnetic activity tends to rise around the equinoxes because of how Earth's tilt aligns its magnetic field with the solar wind, a pattern EarthSky described in its explainer on the equinox connection to aurora season.

Forecasts for the coming days do not fully agree, and readers should know that. EarthSky's Sept. 21 summary said a fast solar wind stream from a coronal hole should arrive later on Sept. 23, making active conditions (Kp 4) likely, with a chance of a G1, or minor, geomagnetic storm (Kp 5) on Sept. 23 and 24. It said aurora could appear over parts of Scotland and southern New Zealand.

The NOAA 3-day space weather forecast issued at 00:30 UTC on Sept. 21 (8:30 p.m. EDT Sept. 20) was more conservative. It put the greatest expected Kp at 2 through Sept. 23, stated that "No G1 (Minor) or greater geomagnetic storms are expected," and set the odds of R1 to R2 radio blackouts at 1% per day. That product was issued before AR4534's delta configuration was reported; it does not cover Sept. 24, and NOAA updates it twice daily, so later versions may differ.

If a G1 storm does develop, its effects are mild. NOAA's space weather scales describe G1 storms as capable of weak power grid fluctuations and minor impacts on satellite operations, with aurora commonly visible at high latitudes. In the United States, that generally means Alaska and, under dark, clear skies, parts of the far northern tier. There is no official forecast for widespread aurora over the Lower 48 at this time.

Watching the Sun Without the Hype

No household action is needed. Minor flares and G1 storms pose no health risk and do not threaten home electronics. The groups most likely to notice any effects are high-frequency radio operators, some GPS and drone users during geomagnetic activity, and satellite operators.

Aurora watchers in Alaska and the northernmost states can check NOAA's planetary K-index on the nights of Sept. 23 and 24. Look for a Kp of 5 or higher, find a spot away from city lights and face north. Be cautious with social media posts claiming dramatic storms or low-latitude auroras, and rely on NOAA's official watches and alerts instead.

The key unknown is whether AR4534 continues to develop or begins to decay. A flare above M-class or an Earth-directed eruption would prompt new NOAA watches or alerts. The bottom line: the Sun has produced a region worth watching near the equinox, but current official guidance points to modest activity, not a major storm.

What Readers Want to Know

What is sunspot AR4534?

It is a sunspot region near the center of the Earth-facing sun that has developed a beta-delta magnetic configuration. It produced 9 of the Sun's 11 flares in the 24 hours before 11 UTC on Sept. 21, all of them minor.

What does a delta configuration mean?

It means opposite magnetic polarities are packed closely together within the region. That arrangement raises the odds of stronger flares but does not guarantee one.

Is a big solar storm coming?

No official forecast calls for a major storm. EarthSky cites a chance of a G1 minor storm on Sept. 23 and 24 from a coronal hole stream, while NOAA's 3-day forecast issued early Sept. 21 expected conditions below storm levels through Sept. 23.

Will I be able to see the northern lights?

If a G1 storm develops, aurora would most likely be visible in Alaska and at other high latitudes. Most of the Lower 48 is unlikely to see it under current forecasts.

Why did the sun go spotless?

Spotless days become more common as the solar cycle declines after its maximum, which arrived in late 2024. Sept. 18 was the first spotless day since Feb. 24.

Why does the equinox matter for auroras?

Around the equinoxes, Earth's orientation makes its magnetic field more receptive to the solar wind, so geomagnetic activity tends to be more frequent in spring and fall.

Can solar flares harm people on the ground?

No. Earth's atmosphere and magnetic field protect people on the surface. Stronger events mainly affect radio, satellites, navigation systems, and, in rare cases, power grids.