The sun put on quite the show this morning (April 23), blasting out not one, not two, but four solar flares in near-perfect harmony. And NASA’s space-based Solar Dynamics Observatory (SDO) caught it on camera.
Solar flares are explosions from the sun’s surface that emit intense bursts of electromagnetic radiation. They occur when magnetic energy builds up in the solar atmosphere and is rapidly released.
The quartet of eruptions came from four regions, three sunspots and one magnetic filament, separated by hundreds of thousands of miles and linked by near-invisible magnetic loops in the sun’s outer atmosphere, known as the corona. These kinds of explosions are called “sympathetic solar flares,” according to Spaceweather.com. They consist of pairs of explosions that occur in near unison at different regions on the sun’s disk. This morning’s event consisted of not a simple pair but a quartet, making it “super-sympathetic”, according to Spaceweather.com.
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Sympathetic solar flares are triggered when instabilities rapidly travel from one region to another along the magnetic loops that join them. As such, much of the Earth-facing portion of the sun was involved in this morning’s solar symphony.
We will have to wait and see if any of the ejected material from the super-sympathetic eruption will impact Earth, as there is a possibility of an Earth-directed coronal mass ejection (CME). CMEs are huge expulsions of plasma and magnetic fields from the sun. When Earth-directed, they can wreak havoc with power grids, telecommunication networks and orbiting satellites and expose astronauts to dangerous doses of radiation.
Conversely, CMEs are a welcomed visitor for skywatchers worldwide as they can trigger impressive aurora displays visible at latitudes beyond their “normal” polar range.
According to Spaceweather.com, multiple CMEs erupted from the sun in the past 24 hours might be heading our way. If just one of them grazes Earth’s magnetic field a minor-class G1 geomagnetic storm could be triggered. The most likely impact dates are April 25 and April 26.
The quadruple blast today could be a sign we are nearing solar maximum, the peak of solar activity during the sun’s 11-year solar cycle, as sympathetic solar flares are considered to increase with an increase in solar activity. Or perhaps we have already reached solar maximum and are entering the decay phase of the solar cycle, as a 2022 study published in Astrophysics and Space Science suggests that sympathetic solar flares predominantly occur in the decay phase of the solar cycle.
Either way, scientists won’t know when solar maximum has occurred until seven months after it’s over due to how the maximum is computed.
