Astro Bob: Forecast — Partly cloudy with a chance for flares
A big sunspot group not only looks amazing (with the proper protection) but may spark aurora-sightings in the coming week.
For the past week, a wonderful sunspot group shaped like a flying swan has been winging its way across the rotating sun. Named Region 3014, anyone with a pair of safe eclipse glasses or a #14 welder's glass can still see this magnetic monstrosity without the use of a telescope. In fact, it's still visible as of Sunday, May 22, in the sun's northern hemisphere off to the western side of the solar disk. Look for a small, dark fleck like a fly on a window.
Sunspots are regions where magnetic energy rises up from inside the sun and chills the surface, making it appear darker in contrast. Sprinkling iron filings around an ordinary magnet will render its otherwise invisible magnetic field as a series of concentric loops and whirls. Similar fields envelop sunspot groups like 3014, but they're about 600 times more intense than a strong refrigerator magnet.
The sun's boiling surface and turbulent atmosphere twists and stretches those loops, which can snap and release their energy in explosions called solar flares. Provided a spot faces approximately in Earth's direction, the cloud of expelled subatomic debris can make the 93-million-mile journey in a matter of days and link directly (sometimes — not always) into the planet's magnetic field.
Once hooked in, the field lines direct the material at high speed into the upper atmosphere over the polar regions, creating an expanding aurora sometimes visible from much lower latitudes. Speaking of which, observers have reported auroras on several nights over the past week including during last Sunday's total lunar eclipse. If you look at a recent graph of magnetic activity — called the Bz — the trace reveals lots of ups and downs. The sun keeps rattling our cage!
On Friday, May 20, I'd hoped to do some observing with my telescope but encountered a wall of clouds. Through occasional cracks and holes I noticed that the northern sky glowed softly with aurora. Although the possibility for northern lights looks slim on paper for Sunday night, May 22, I wouldn't be surprised if we got some anyway thanks to ongoing flare ejecta and high-speed particles streaming from coronal holes .
During its run, Region 3014 has produced a bunch of small and moderate-sized flares. NOAA's Space Weather Prediction Center forecasts a 99% chance for C-class (small) flares, 40% for M-class (moderate) and 5% for X-class (major) flares on Sunday, May 22. Should a flare occur we'd potentially expect aurora a few nights from now. I've also been keeping my eye on Region 3017. It's been growing all along and may have surprises in store.
The current Solar Cycle 25 has been much stronger than originally forecast. Expected to peak in July 2025, we're seeing as many sunspots on average now as the original forecast predicted for June 2023. Yup, we're way ahead of schedule.
Solar cycles average 11 years, beginning at solar minimum, when few if any sunspots are observed, and then ramp up to maximum. After the past couple of weak cycles solar observers and aurora watchers are definitely ready to rock and roll!
"Astro" Bob King is a freelance writer for the Duluth News Tribune.