Origin of magnetic field covering Sun discovered
A team of scientists has discovered the origin of the magnetic field covering the Sun.
Washington: A team of scientists has discovered the origin of the magnetic field covering the Sun.
The magnetic field that covers the Sun and determines its behavior, the eleven year cycles no less than such conspicuous phenomena as solar spots and solar storms, also has another side to it, that is, a magnetic web that covers the entire surface of the Sun at rest and whose net magnetic flow is greater than that of the active areas.
A study led by the Institute of Astrophysics of Andalusia (IAA-CSIC) has revealed where the flow that feeds this web comes from.
The outline of the solar magnetic web coincides with the boundaries of the so-called supergranules, structures linked to the existence of hot gas rising to the surface (similar to the bubbles made by boiling water) some twenty thousand kilometers in diameter.
Researcher Milan Gosic said that they have discovered that inside these supergranules, in what is known as intranetwork, small magnetic elements appear which travel toward the outer boundaries and interact with the web.
These heretofore little known elements can generate and transfer, in the span of barely fourteen hours, the entire magnetic flow detected on the web. Bearing in mind that only about 40 percent of this flow ends up on the web, they found that the intranetwork can replenish the flow of the web in twenty four hours, says Luis Bellot.
The finding was made in the course of extraordinarily long temporal sequences of observation, about forty hours, using the high resolution Japanese HINODE satellite, a record for this type of instruments, which made it possible to monitor the evolution of supergranular cells throughout their life.
Bellot added that it is believed that the magnetic elements of the intranetwork and their interactions with the web might be responsible for the warming up of the outer layers of the Sun's atmosphere, one of the most pressing unsolved problems of Solar Physics.
The study is published in The Astrophysical Journal.