Enigmatic sun: the calm before the next storm

On the surface of our sun is currently very quiet. There are no significant sunspots are observed. Those spectacular outbreaks, and the typically solar Plasma o

Enigmatic sun: the calm before the next storm

On the surface of our sun is currently very quiet. There are no significant sunspots are observed. Those spectacular outbreaks, and the typically solar Plasma out into space in addition to skidding. The reason is that the Central star of our planetary system is currently in the Minimum of the sunspot cycle, which varies in the rhythm of eleven years. The next Maximum is only to be expected for the year 2025, and 2026 to. For a long time puzzles the scientists, what is behind this periodic cycle of our sun. A group of researchers from Göttingen passed the causes on the reason. She has also found out why the sun spots moving in the direction of the sun's equator.

The search for the causes of the solar cycle is by no means only of academic interest. A solar Maximum pleased, for example, an Amateur radio operator. Because then propagated from the sun escaping electrically charged particles to stimulate the different layers in the ionosphere high above the surface of the earth. Of the earth's emitted radio waves are reflected, which enables wireless connections around the globe. The increased solar activity during a maximum but also entails considerable risks. In these phases of the solar surface emanating from the magnetic storms can get many electrically-charged, highly energetic particles that satellites fail and power grids in higher earth Wide break under the load of the induced currents together.

Since the Dessau astronomer Samuel Heinrich Schwabe in 1843, discovered that the number of the sun varies stain rhythmically with a period of about eleven years, researchers have searched for the causes of this the whole of the sun's dominant cycle. While Schwabe was based his observation solely on the number of dark spots on the sun's surface, discovered by the American astronomer George Hale about 60 years later, that these spots are the source of strong magnetic anomalies on the sun. In the course of a cycle, all spots have the same magnetic polarity. In the subsequent period, they are polarized in contrast, all of the in the opposite direction. Hale concluded that the actual rhythm of the sun takes 22 years. For it is only after two successive sunspot cycles, the sun's surface reaches again its original magnetic state.

seismology of the sun

it has long Been thought that convection currents of hot Plasma within the sun are for these rhythmic fluctuations to be responsible. Because plasma particles are electrically charged, can generate a flowing Plasma huge magnetic fields. So far it was not known how large the extent of these flows of Plasma and how they spread out within the sun. Scientists from the Max-Planck-Institute for solar system research, and researchers from the University of Göttingen have now found in the evaluation of long-term measurements of the sun, an answer to these questions.

The researchers, Laurent Gizon came in the convection currents with the same methods, to track which seismic the Interior of the earth lodges to explore. Geoscientists use earth's ongoing earthquake waves, similar to an x-Ray image in medical diagnostics – the Interior of our planet to Shine through. Also in the sun, there are mechanical vibrations that pass through as waves, the sun, and as strong vibrations on the surface of the sun are felt. Our Central star is no Seismometer that could detect such oscillations exist. The vibrations show, but in detailed shots of the sun's surface. These serve as the basis of the so-called Helioseismologie.

reports such As Gizon and his colleagues in the journal "Science," they analyzed recordings of a 23-year-long measurement series of various observations of the Sun. They drew both on data from the American space Agency Nasa and the European space Agency, Esa-operated satellite "Soho" and of the American solar Observatory "Solar Dynamics Observatory", as well as the shots of an international network of ground-based solar telescopes.

Drift magnetic anomalies

From the data, the researchers determined the velocity of propagation of seismic vibrations on the surface of the sun and calculated from this the structure of the convection currents of the plasma in the solar interior. They discovered several different flows. It showed that the most intense flow along the solar meridians from the solar equator towards the poles. In higher solar Latitudes immerse yourself up to 200,000 kilometres deep in the sun. There, they flow back to the Equator and to rise again to the vicinity of the surface.

Each of these streams, approximately the top one-third of the total solar body, is running with it. Researchers were surprised, as you determined from the propagation speed of the flows of the circulation period. It amounted to almost exactly 22 years, and corresponded so exactly to the duration of a full solar cycle.

Updated Date: 21 July 2020, 06:19

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