Three Massive Earth-Facing Sunspots Have Developed 'Delta' Magnetic Fields

The sun is having a busy week, developing three massive unstable "delta-class" sunspots, one of which spewed out the second biggest solar flare so far this solar cycle.

The flare, which was classified as an X1.9 flare, occurred at 1:50 p.m. EST on January 9, 2023, and erupted from sunspot AR3184, NASA said in a statement. There are two other large sunspots currently on the sun's surface also at risk of releasing an X-class solar flare: AR3181 and AR3182.

Solar flares are powerful jets of electromagnetic radiation shot out from the sun, usually from sunspots when their twisted magnetic field lines suddenly realign. X-class flares are the most powerful type of solar flare, and if they directly hit the Earth, can lead to radiation storms and planet-wide radio blackouts.

This flare caused minor radio blackouts over the Pacific Ocean.

"Solar flares are classified according to how bright they are in the soft X-ray part of the spectrum," Gonzalo José Carracedo Carballal, an astrophysics researcher at the Instituto Nacional de Técnica Aeroespacial in Madrid, Spain, previously told Newsweek.

Solar flares are classified as A-class, B-class or C-class at their weakest, M-class at a moderate strength, and X-class at their most powerful. X-class flares are 10 times more powerful than M-class, and an X10 flare is 10 times more powerful than an X1 flare.

The January 9 flare was classified at an X1.9 flare, making it the second most powerful flare seen in solar cycle 25 so far. Solar cycles follow 11-year patterns of activity: This solar cycle, the 25th since we began recording solar activity in 1749, began in 2019 after the last solar minimum, and is now revving up in activity as it approaches the next solar maximum in 2025, with increased numbers of sunspots and solar flares expected in the coming years.

The most powerful flare of solar cycle 25 occurred on April 4, 2022, when an X2.2 flare was measured.

AR3184, which released the January 9 flare, and its fellow sunspots AR3181, and AR3182, each have a 'delta-class' magnetic field, spaceweather.com stated, making them unstable and increasingly prone to emitting strong and powerful flares and coronal mass ejections (CMEs).

Delta-class magnetic fields, as defined by spaceweatherlive.com, mean that there are multiple magnetic field lines all with different polarities interacting at the sunspot, making them more unstable and so more likely to release solar flares.

These unstable sunspots and their delta-class magnetic fields have contributed to NOAA forecasters' estimate of there being a 35 percent chance of another X-flare on January 10. This frequency of X-class flares is unusual, as X-class flares usually only happen around 10 times per year.

"In 2022 we saw 7 X-class #SolarFlares (up from 2 in 2021). We're nine days into 2023, and the second X-class flare of the year is already in progress!" tweeted Ryan French, a solar physicist at the National Solar Observatory.

Before January 9, the most recent X-class flares occurred on January 6, 2023, when an X1.22 flare was recorded, and on October 2, 2022, with an X1 flare.

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