It is the emergence of magnetic 'tangles' on the surface of the Sun that produces the active regions from which violent eruptions of particles and ionized gas capable of also affecting the Earth can start: this is demonstrated by the data collected by the Solar Dynamic Observatory satellite (Sdo ) of NASA, published in Nature Communications by an international group led by David MacTaggart of the University of Glasgow, in which Paolo Romano and Salvatore Guglielmino of the National Institute of Astrophysics (INAF) of Catania participated among others.
The most violent eruptions in the Solar System originate in the active regions of the Sun, areas where there are intense magnetic fields that can be very complex and tangled. Knowing the properties of the twisted lines of the solar magnetic field is fundamental to understanding the mechanism of triggering solar flares (flare) and coronal mass ejections (CME), phenomena that release large amounts of energy, particles and ionized gas and which can have important effects also on the terrestrial environment. One of the most debated questions so far is whether the 'twist' of magnetic fields emerges on the solar surface by rising with its active region or is instead created in the solar atmosphere. To find out,the researchers focused on the emergence of an active region (Noaa 11318) that they had already studied in 2014. Comparing the observations with numerical simulations, they found that active regions arise from the emergence of already twisted magnetic flux tubes.
“For the first time we have obtained a direct measurement of the magnetic field topology of an active region observed during its emergence in the photosphere”, explains Guglielmino.
"The 'twist' process is essential for triggering the phenomena of energy release in the solar atmosphere, so having the ability to determine from the early stages of the emergence of an active region its topology, more or less twisted, will allow us to better understand its eruptive potential.
This will increase our ability to make more accurate forecasts also in the field of space weather ".