SANTA CRUZ DE TENERIFE, May 25. (EUROPE PRESS) –
An international scientific team, in which researchers from the Instituto de Astrofísica de Canarias (IAC) and the University of La Laguna (ULL) participate, have discovered magnetic waves in sunspots with such a high energy flux that they could maintain the atmosphere from the Sun to millions of degrees.
The finding, published in the journal Nature Astronomy, adds a new missing piece to the “puzzle” of why the Sun’s outer layers are hotter than its surface despite being further away from the heat source.
From the IAC they point out in a note that the Sun shines thanks to the nuclear fusion of hydrogen in its nucleus, where the temperature reaches 16,000,000 °C, while on the visible surface (or photosphere) of the Sun, the temperature drops to about 5,000°C.
It is intuitive that hydrogen gas located further from its core is colder, however, the solar corona, which is further from the core than the photosphere, reaches temperatures of millions of degrees.
No theory has been able to explain this paradox, known as the coronal heating problem, which has challenged the scientific community for a century, the IAC insists.
Using the Big Bear Solar Observatory’s 1.6-metre ‘Goode’ solar telescope, an international scientific team detected oscillations in dark elements of a large sunspot, which is the coldest structure on the Sun. These obscurations are plasma fibrils aligned with a strong magnetic field of high intensity in the sunspot.
“These filaments oscillate transversely, which means that it is a transverse magnetohydrodynamic (MHD) wave and that they are capable of dragging the magnetic field lines to move laterally,” explains Yuan Ding, a researcher at the Harbin Institute of Technology (China) who has led the investigation.
This implies, he adds, “that the oscillations of the fibrils could provide a very high energy flow.”
The scientific team has developed a mathematical model of the fast transverse waves in sunspots and has calculated that the energy flux is between 1,000 and 10,000 times greater than the energy released in the plasma of the active region, which would be sufficient. to keep the Sun’s atmosphere at millions of degrees of temperature.
“In the study, the plasma parameters were estimated by applying an inversion code developed at the IAC to the observations”, points out Juan C. Trelles, co-author of the article and researcher at the IAC and ULL.
Of these two scientific institutions, researchers Carlos Quintero and Basilio Ruiz have also participated.
THERE WILL BE MORE INVESTIGATIONS
In addition to this scientific result, the study is accompanied by extremely high spatial resolution data from the darkest area of the sunspot or umbra, as well as the dynamics of high-energy waves in its plasma fibrils.
The research thus provides unprecedented insight into the strongly magnetized plasma region of the Sun and plays a leading role in resolving the coronal heating problem.
The Solar Physics community plans to carry out further research using the latest generation solar telescopes that will be available in the coming years, such as the European Solar Telescope (EST), which is scheduled to be installed at the Roque de los Muchachos Observatory in The Palm.
