A remarkably uncommon, "quadruple" solar flare has just erupted from four distinct points across the sun's surface nearly simultaneously. The elements of this interlinked, explosive quartet might have also unleashed a solar storm headed towards Earth — which could potentially collide with our planet in the forthcoming days.
The four-part eruption commenced at approximately 1:00 a.m. EDT on Tuesday (April 23), as per video footage captured by NASA's Solar Dynamics Observatory. The almost synchronous bursts emanated from three sunspots and a substantial magnetic filament — a vast loop of plasma suspended above the solar surface — positioned amidst those three dark patches, as reported by Spaceweather.com. The eruption sites were each spaced by hundreds of thousands of miles, with the region between covering roughly a third of the solar surface facing Earth.
The simultaneous eruptions were part of a single outburst, termed a sympathetic solar flare. This category of solar eruption occurs when sunspots or filaments are invisibly connected by immense magnetic field loops arching above the solar surface. When one erupts, the others promptly follow suit.
In nearly all documented instances of such occurrences, sympathetic flares involve merely two connected flares, varying in intensity from minor eruptions to X-class flares, the sun's most potent class of solar flares. Nonetheless, in this instance, there were twice as many flares as usual, rendering this a "super-sympathetic" flare, according to Spaceweather.com.
The combined force of the eruption remains presently uncertain. However, considering the expansive area covered by the sunspots, there exists a fair chance that "at least some of the debris will be Earth-directed," as per Spaceweather.com. This debris would likely manifest as a massive cloud of plasma and radiation propelled by one of the flares, known as a coronal mass ejection (CME). If confirmed, a CME could collide with our planet in the ensuing days, potentially triggering vibrant auroras near its magnetic poles.
This marks at least the third sympathetic solar flare of 2024, following a pair of eruptions in January and an X-class flare pair in March.
Sympathetic solar flares are more prone to occur during or around solar maximum, the sun's most active phase in its roughly 11-year solar cycle, according to a 2022 study analyzing nearly four decades of solar flare data. Some researchers posit that this explosive apex may have already commenced, roughly a year earlier than initially projected.
In addition to ushering in more frequent and potent solar storms, the solar maximum also brings about an increase in the number of sunspots scattered across the sun. At the dawn of Tuesday, there were 14 sunspot groups on the sun's near side — equalling the record for the highest sunspot total since the onset of the current solar cycle in 2019, as reported by EarthSky.
