Loops of hot electrified gas above an active sunspot
© NASA/Standford University
American Geophysical Society Meeting, San Francisco, December 2001
The Sun’s violent outbursts have deep and twisted origins.
The Sun’s violent eruptions of material and magnetic energy have deep and twisted origins, researchers told this week’s American Geophysical Union Meeting in San Francisco, California.
Sunspots have been studied for centuries, but were thought to be exclusively a surface phenomenon. The researchers find that they in fact extend at least 100,000 kilometres below the Sun’s surface. "This is the first evidence that their roots go deep into the interior," says team member Alexander Kosovichev.
An examination of another sunspot by Junwei Zhao, also of Stanford, reveals magnetic field lines beneath the surface twisting around one another into bunches as the sunspot forms. "A huge amount of energy builds up in these bunches," says Zhao. When released, this would trigger a CME hurling solar material into space.
Sunspots had been observed rotating before, says Richard Nightingale, a solar physicist at Lockheed Martin in Palo Alto, California. "The coupling of above and below - that’s all new," he says.
Beneath the surface
"The interior of the Sun was simple before there were data," says Philip Scherer, who led the research. Models of the Sun’s interior assumed that buoyant hot material rose to the surface, where it was whipped up by the magnetic field lines that criss-cross the star’s exterior, forming sunspots and leading to CMEs.
Now it appears that material rising from deep within the Sun can twist magnetic field lines, giving them more energy. "Convection is being converted into magnetic fields," says Scherer.
This may produce the giant loops of overstretched magnetic fields that arch out of sunspots. The snapping of these loops releases energy, causing CMEs. Why the processes occur at specific locations is still a mystery.
The structure below the surface is currently too complicated to predict accurately, according to George Fisher, who models the Sun’s behaviour at the University of California at Berkeley. More data from sunspots may reveal patterns in the rising solar material and their interactions with magnetic field lines. "In about five years’ time we should be able to model some kind of real events," he says.
Fisher aims to use data from SOHO and future missions to model the Sun’s magnetic field completely. Then he hopes to be able to spot CMEs stirring within the Sun and to forecast the resulting weather in space.
TOM CLARKE | © Nature News Service
New quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of Technology
Light rays from a supernova bent by the curvature of space-time around a galaxy
21.04.2017 | Stockholm University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
24.04.2017 | Life Sciences
24.04.2017 | Earth Sciences
24.04.2017 | Machine Engineering