A gigantic sunspot, almost 12 times the size of the Earth, has put our planet in its sights in the last few hours and could cause intense geomagnetic storms. The spot, called AR3576, is made up of four darker nuclei and extends overall for over 150,000 kilometres: it is so large that it is also visible from Earth (with due precautions to protect the eyes). According to the American Atmospheric and Oceanic Agency (NOAA), this sunspot could generate strong X-class solar flares, the most powerful.
An X3.38 class solar flare has already been recorded today, among the strongest recorded in the current solar cycle after the solar eruption at the beginning of the year. The solar flare – which began when it was 2pm in Italy – caused brief radio silences over the South Atlantic Ocean. In particular, there are blackouts in global communications at frequencies below 5 MHz. The main areas affected are Africa, South America and the South Atlantic.
The very intense flare could be accompanied by a coronal mass ejection, i.e. an expulsion of material from the solar corona which, by interacting with the Earth’s magnetic field, could produce intense aurora borealis. Luckily the flare occurred on the “hidden” side of the Sun and will not hit the Earth directly.
Departing sunspot region 3575 which is already behind the south-west limb was the source of the major X3.3 solar flare which peaked at 13:14 UTC. The resulting coronal mass ejection is impressive but of course not aimed at our planet. pic.twitter.com/MHHN7uQ012
— SpaceWeatherLive (@_SpaceWeather_) February 9, 2024
Solar flares, also called solar flare, they are violent explosions of the Sun: during flares, the solar plasma can reach temperatures well above 10 million degrees and a luminosity that can exceed that of the entire corona.
Flares have a characteristic pattern of brightness: a sudden increase, followed by a much more gradual decrease. They do not last long, from a few minutes to a few hours at most, and are localized in small regions on the surface of the Sun. Sometimes the strength of the flare is such as to generate solar flares, with clouds of plasma that are projected into space. The resulting shock waves travel laterally through the photosphere and upward through the chromosphere and corona, at speeds on the order of 5 million kilometers per hour.
Flares are more frequent in periods of high solar activity, in the presence of intense magnetic fields of the spots. The cause of flare is traced back to magnetic instabilities, which accelerate particles and release energy rapidly, causing a sudden increase in brightness, followed by a more gradual cooling. The energetic particles emitted by these solar phenomena are primarily responsible for the Northern and Southern Lights.