Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Space Instrument Adds Big Piece to the Solar Corona Puzzle

24.01.2013
The Sun's visible surface, or photosphere, is 10,000 degrees Fahrenheit. As you move outward from it, you pass through a tenuous layer of hot, ionized gas or plasma called the corona. The corona is familiar to anyone who has seen a total solar eclipse, since it glimmers ghostly white around the hidden Sun.
But how can the solar atmosphere get hotter, rather than colder, the farther you go from the Sun's surface? This mystery has puzzled solar astronomers for decades. A suborbital rocket mission that launched in July 2012 has just provided a major piece of the puzzle.

The High-resolution Coronal Imager, or Hi-C, revealed one of the mechanisms that pumps energy into the corona, heating it to temperatures up to 7 million degrees F. The secret is a complex process known as magnetic reconnection.

"This is the first time we've had images at high enough resolution to directly observe magnetic reconnection," explained Smithsonian astronomer Leon Golub (Harvard-Smithsonian Center for Astrophysics). "We can see details in the corona five times finer than any other instrument."

"Our team developed an exceptional instrument capable of revolutionary image resolution of the solar atmosphere. Due to the level of activity, we were able to clearly focus on an active sunspot, thereby obtaining some remarkable images," said heliophysicist Jonathan Cirtain (Marshall Space Flight Center).

Magnetic braids and loops
The Sun's activity, including solar flares and plasma eruptions, is powered by magnetic fields. Most people are familiar with the simple bar magnet, and how you can sprinkle iron filings around one to see its field looping from one end to the other. The Sun is much more complicated.

The Sun's surface is like a collection of thousand-mile-long magnets scattered around after bubbling up from inside the Sun. Magnetic fields poke out of one spot and loop around to another spot. Plasma flows along those fields, outlining them with glowing threads.

The images from Hi-C showed interweaved magnetic fields that were braided just like hair. When those braids relax and straighten, they release energy. Hi-C witnessed one such event during its flight.

It also detected an area where magnetic field lines crossed in an X, then straightened out as the fields reconnected. Minutes later, that spot erupted with a mini solar flare.

Hi-C showed that the Sun is dynamic, with magnetic fields constantly warping, twisting, and colliding in bursts of energy. Added together, those energy bursts can boost the temperature of the corona to 7 million degrees F when the Sun is particularly active.

Selecting the target
The telescope aboard Hi-C provided a resolution of 0.2 arcseconds - about the size of a dime seen from 10 miles away. That allowed astronomers to tease out details just 100 miles in size. (For comparison, the Sun is 865,000 miles in diameter.)

Hi-C photographed the Sun in ultraviolet light at a wavelength of 19.3 nanometers - 25 times shorter than wavelengths of visible light. That wavelength is blocked by Earth's atmosphere, so to observe it astronomers had to get above the atmosphere. The rocket's suborbital flight allowed Hi-C to collect data for just over 5 minutes before returning to Earth.

Hi-C could only view a portion of the Sun, so the team had to point it carefully. And since the Sun changes hourly, they had to select their target at the last minute - the day of the launch. They chose a region that promised to be particularly active.

"We looked at one of the largest and most complicated active regions I've ever seen on the Sun," said Golub. "We hoped that we would see something really new, and we weren't disappointed."

Next steps
Golub said that data from Hi-C continues to be analyzed for more insights. Researchers are hunting areas where other energy release processes were occurring.

In the future, the scientists hope to launch a satellite that could observe the Sun continuously at the same level of sharp detail.

"We learned so much in just five minutes. Imagine what we could learn by watching the Sun 24/7 with this telescope," said Golub.

This research is being published in the journal Nature in a paper co-authored by Cirtain, Golub, A. Winebarger (Marshall), B. De Pontieu (Lockheed Martin), K. Kobayashi (University of Alabama - Huntsville), R. Moore (Marshall), R. Walsh (University of Central Lancashire), K. Korreck, M. Weber and P. McCauley (CfA), A. Title (Lockheed Martin), S. Kuzin (Lebedev Physical Institute), and C. DeForest (Southwest Research Institute).

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

For more information, contact:

David A. Aguilar
Director of Public Affairs
Harvard-Smithsonian Center for Astrophysics
617-495-7462
daguilar@cfa.harvard.edu
Christine Pulliam
Public Affairs Specialist
Harvard-Smithsonian Center for Astrophysics
617-495-7463
cpulliam@cfa.harvard.edu

Christine Pulliam | EurekAlert!
Further information:
http://www.cfa.harvard.edu
http://www.cfa.harvard.edu/news/2013/pr201303.html

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>