Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spotting Ultrafine Loops in the Sun's Corona06.12.12

13.06.2012
A key to understanding the dynamics of the sun and what causes the great solar explosions there relies on deciphering how material, heat and energy swirl across the sun's surface and rise into the upper atmosphere, or corona.

Tracking the constantly moving material requires state-of-the-art telescopes with the highest resolution possible. By combining images from NASA's Solar Dynamics Observatory (SDO) and a new generation telescope called the New Solar Telescope (NST) at Big Bear Solar Observatory in Big Bear City, Calif. scientists have for the first time observed a new facet of the system: especially narrow loops of solar material scattered on the sun's surface, which are connected to higher lying, wider loops. These ultrafine loops, and their wider cousins may also help with the quest to determine how temperatures rise throughout the corona.


Left: An image of a magnetic loop complex as captured on July 22, 2011 by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory. The image shows light in the 193 Angstrom wavelength. Credit: NASA/SDO/AIA
Right: This covers the area of the sun roughly in the middle of that shown in the SDO image on the left, as captured by the New Space Telescope. Together the images were used to observe and analyze ultrafine loops of magnetized material in the sun's atmosphere. Credit: NST

"We're used to seeing magnetic loops on the sun," says Philip Goode of the New Jersey Institute of Technology in Newark, NJ, who was a co-author on a paper on these results in the Astrophysical Journal on May 1, 2012. "But we've never seen ones lying so low, that were so cold, or that were so narrow. These loops are 10 times narrower and at least 10 times cooler than the higher loops often seen by SDO."

Goode and his colleagues, Wenda Cao and Haisheng Ji used the two telescopes to observe these loops in data from July 22, 2011. The combination of NST and SDO allowed the researchers to trace the flow of energy from the cooler ultrafine loops observed with NST to cospatial and cotemporal brightenings seen by SDO in the overlying million degree corona. In the NST observations, the loops show a nearly consistent width of what Goode says is a "surprisingly narrow diameter" of only about 60 miles across. The team aligned images from the NST, which can measure magnetic fields to high resolution, with the SDO images to find the magnetic footprint of these loops on the sun. The magnetic maps showed that the loops lined up with fine lanes on the sun that separate what's known as granules – cells on the star's surface that can be loosely understood as bubbles of boiling solar material that rise up from below. After the material, or plasma, rises up into the granules, it sweeps out to the sides, and flows back down these intergranular lanes. The lanes are consequently believed to contain concentrated magnetic fields, the perfect place for the origin of these newly spotted magnetic loops. The very position and shape of the ultrafine loops, therefore, help confirm models of the sun's surface.

Goode and his colleagues did more than just categorize the size and shape of the loops, however. They also tracked the loops through time as they rose up into the sun's corona, a process that may help solve a persistent question in solar physics, namely why the sun's atmosphere, or corona is so hot.

Scientists in the early 1940s discovered that the sun's atmosphere is some thousand times hotter than its surface. Determining just what processes heat those gases up to millions of degrees has been a key research area ever since.

"There have been many suggestions over the years as to what mechanism can make the atmosphere a thousand times hotter than the surface of the sun," says Goode. "They basically come in two categories. The first is that there's some kind of continuous magnetic energy adding heat. The second is that there's an impulsive, intermittent movement that adds heat. And there are, of course, all kinds of variations and mixtures of each theme."

In this case, the appearance of the ultrafine loops seems to be correlated to intense magnetic field collisions. The largest groups of loops also corresponded to solar phenomena called Type II spicules, which some theories postulate contribute to coronal heating.

"We observe an impulsive event at the sun's surface, and this excites low-lying and higher-lying, wider loops almost simultaneously," says Goode. "It's just a correlation at this point, but for the first time we've observed something happen at the surface and we can track it up through heating of the corona. This doesn't answer the question of whether it's the only mechanism that heats the corona, but it certainly seems to be at least one mechanism."

In addition to the value of having seen such fine structures for the first time, Goode and his colleagues believe this is a great example of how the NST can coordinate with other instruments, such as an upcoming NASA Explorer called the Interface Region Imaging Spectrograph or IRIS, due to launch no earlier than December 2012. IRIS will focus exclusively on the area of the sun's atmosphere at the base of the corona, an area crucial for coronal heating. The NST's capabilities will mesh nicely with this since it can measure magnetic fields in the same regions IRIS will be observing.

For more information about the IRIS mission, visit:
http://science.nasa.gov/missions/iris/
Karen C. Fox
NASA's Goddard Space Flight Center

Susan Hendrix | EurekAlert!
Further information:
http://www.nasa.gov
http://www.nasa.gov/mission_pages/sunearth/news/corona-loops.html

More articles from Physics and Astronomy:

nachricht When helium behaves like a black hole
22.03.2017 | University of Vermont

nachricht Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars
22.03.2017 | International Centre for Radio Astronomy Research

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Pulverizing electronic waste is green, clean -- and cold

22.03.2017 | Materials Sciences

Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars

22.03.2017 | Physics and Astronomy

New gel-like coating beefs up the performance of lithium-sulfur batteries

22.03.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>