Sunspot AR4566 Turns Magnetically Complex: X-Class Flare Risk and Aurora Outlook

A fast-growing sunspot on the Earth-facing side of the Sun has become the one to watch this week. Sunspot AR4566 developed a “beta-gamma-delta” magnetic field on 3–4 November 2026, the most complex type that solar forecasters track, and the kind most likely to produce strong M-class and X-class solar flares. At the same time, a glancing blow from a coronal mass ejection (CME) and a stream of fast solar wind could stir up Earth’s magnetic field between 5 and 9 November, giving high-latitude skywatchers a chance of auroras.

Here is what is happening on the Sun, what the official forecasts say, and what it could mean for radio, satellites and the northern lights.

What is sunspot AR4566?

Sunspots are dark, cooler patches on the Sun’s surface where intense magnetic fields poke through and block the flow of heat from below. Each new group is given a number by the U.S. National Oceanic and Atmospheric Administration (NOAA); AR stands for “active region”. AR4566 appeared in early November and grew quickly over 3–4 November, while two smaller regions nearby, AR4564 and AR4565, stayed simple and quiet.

What makes AR4566 stand out is its magnetic classification. Forecasters describe sunspot groups with Greek letters:

• Alpha: a single magnetic polarity, usually calm.
• Beta: two opposite polarities, clearly separated.
• Gamma: polarities mixed together irregularly.
• Delta: opposite polarities squeezed together inside the same dark core (umbra).

A beta-gamma-delta region combines all the warning signs. When opposite magnetic fields are crowded together and twisted, they can suddenly snap and reconnect, releasing the energy as a solar flare and sometimes a CME. Most of the biggest flares of each solar cycle come from delta regions.

How likely is a strong solar flare?

So far AR4566 has been more promise than action. In the 24 hours to 11:00 UTC on 4 November, the Sun produced 12 small flares, two C-class and ten B-class, six of them from AR4566. The strongest was a C1.2 flare at 06:54 UTC on 4 November.

Forecasts on 4 November gave about a 25% chance of an M-class flare and a 10% chance of an X-class flare in each of the next two days. NOAA’s Space Weather Prediction Center (SWPC) put the chance of R1–R2 (minor to moderate) radio blackouts at 25% per day and of R3 or stronger blackouts at 10% per day for 4–6 November.

Flares are graded on a scale of A, B, C, M and X, where each letter is ten times stronger than the one before. C-class flares are common and harmless. M-class flares can cause brief radio blackouts on the sunlit side of Earth. X-class flares are the strongest; they can disrupt high-frequency radio and GPS accuracy for an hour or more and are often accompanied by CMEs.

Will there be auroras this week?

A flare alone does not cause auroras. The northern and southern lights are produced when a CME or a fast stream of solar wind reaches Earth and shakes the magnetic field around our planet. Two possible sources are in play this week:

• A CME launched around 15:00 UTC on 1 November had a component heading in Earth’s direction and could deliver a weak glancing blow around 5 November.
• A high-speed stream of solar wind from a coronal hole could reach Earth around 7–9 November.

The official outlook is modest. NOAA’s 3-day forecast issued on 4 November expected the Kp index to peak around 4 on 5 November and did not expect any G1 (minor) geomagnetic storm, with quiet conditions returning on 6 November. That means auroras are most likely only at high latitudes: northern Scandinavia, Iceland, Alaska and northern Canada, and in the south, Tasmania and New Zealand’s South Island under clear, dark skies. If AR4566 fires a strong flare with an Earth-directed CME, the picture could change quickly, so it is worth checking for updates.

You can follow the live Kp index, solar wind and aurora outlook on our space weather dashboard; our space weather dashboard guide explains what each number means.

What a strong flare could affect

For most people a solar flare is invisible and harmless. Earth’s atmosphere and magnetic field protect us on the ground. The effects show up in technology:

• Radio: X-ray bursts from a flare can briefly black out shortwave (HF) radio used by aircraft, ships and radio amateurs on the daylit side of Earth.
• GPS: disturbances in the ionosphere can reduce positioning accuracy for a few hours.
• Satellites: geomagnetic storms heat and expand the upper atmosphere, increasing drag on satellites in low orbit. That same effect, sustained over the current active solar cycle, helped bring down NASA’s Swift observatory, which re-entered on 4 November.
• Power grids: only very strong (G4–G5) storms pose a risk to power networks, and none is forecast.

Where are we in the solar cycle?

The Sun goes through an 11-year cycle of activity. Solar Cycle 25 passed its maximum around late 2024 and is now slowly declining, although activity remains high. Large, complex sunspots can still appear for several years after the peak, and some of the most powerful flares in history came during the declining phase of a cycle. In February 2026 another sunspot, AR4366, produced an X8.1 flare, one of the strongest of this cycle. AR4566 is far smaller so far, but delta regions can grow and change quickly over a few days.

How to watch the Sun safely

Never look directly at the Sun, and never point binoculars or a telescope at it without a proper certified solar filter fitted over the front of the instrument. The easiest safe way to see AR4566 is through the free daily images from NASA’s Solar Dynamics Observatory, or by projecting the Sun’s image through a small telescope onto a white card. With a certified solar filter, a large sunspot group can even be seen with the eye alone.

If you are hoping for auroras, check the Kp index after dark, get away from city lights and look towards the polar horizon. Our best time to stargaze tonight tool shows cloud cover and darkness for your location, and the upcoming space events page lists other sights this month, including the Leonid meteor shower on 17 November and the Supermoon on 24 November.

Sources: NOAA Space Weather Prediction Center; NOAA 3-day forecast, 4 November 2026 (via SpaceWeatherLive); EarthSky: Sun news, 4 November 2026; Spaceweather.com.