Bright points in Sun's atmosphere mark patterns deep in its interior

Apr 17, 2014 by Karen C. Fox
Brightpoints in the sun's atmosphere, left, correspond to magnetic parcels on the sun's surface, seen in the processed data on the right. Green spots show smaller parcels, red and yellow much bigger ones. Images based on data from NASA's SDO captured at 8 p.m. EDT on May 15, 2010. Credit: NASA/SDO

Like a balloon bobbing along in the air while tied to a child's hand, a tracer has been found in the sun's atmosphere to help track the flow of material coursing underneath the sun's surface.

New research that uses data from NASA's Solar Dynamics Observatory, or SDO, to track bright points in the solar atmosphere and magnetic signatures on the sun's surface offers a way to probe the star's depths faster than ever before. The technique opens the door for near real-time mapping of the sun's roiling interior – movement that affects a wide range of events on the sun from its 22-year sunspot cycle to its frequent bursts of X-ray light called solar flares.

"There are all sorts of things lurking below the surface," said Scott McIntosh, first author of a paper on these results in the April 1, 2014, issue of the Astrophysical Journal Letters. "And we've found a marker for this deep rooted activity. This is kind of a gateway to the interior, and we don't need months of data to get there."

One of the most common ways to probe the sun's interior is through a technique called helioseismology in which scientists track the time it takes for waves – not unlike seismic waves on Earth—to travel from one side of the sun to the other. From helioseismology solar scientists have some sense of what's happening inside the sun, which they believe to be made up of granules and super-granules of moving solar material. The material is constantly overturning like boiling water in a pot, but on a much grander scale: A granule is approximately the distance from Los Angeles to New York City; a super-granule is about twice the diameter of Earth.

SDO contains three instruments; Helioseismic and Magnetic Imager (HMI), Atmospheric Imaging Assembly (AIA), and Extreme Ultraviolet Variablity Experiment(EVE) -- for observations leading to a more complete understanding of the solar dynamics that drive variability in the Earth's environment. Credit: NASA/Goddard Space Flight Center

Instead of tracking seismic waves, the new research probes the solar interior using the Helioseismic Magnetic Imager on NASA's Solar Dynamics Observatory, or SDO, which can map the dynamic magnetic fields that thread through and around the sun. Since 2010, McIntosh has tracked the size of different magnetically-balanced areas on the sun, that is, areas where there are an even number of magnetic fields pointing down in toward the sun as pointing out. Think of it like looking down at a city from above with a technology that observed people, but not walls, and recording areas that have an even number of men and women. Even without seeing the buildings, you'd naturally get a sense for the size of rooms, houses, buildings, and whole city blocks – the structures in which people naturally group.

The team found that the magnetic parcels they mapped corresponded to the size of granules and supergranules, but they also spotted areas much larger than those previously noted—about the diameter of Jupiter. It's as if when searching for those pairs of men and women, one suddenly realized that the city itself and the sprawling suburbs was another scale worth paying attention to. The scientists believe these areas correlate to even larger cells of flowing material inside the sun.

The researchers also looked at these regions in SDO imagery of the sun's atmosphere, the corona, using the Atmospheric Imaging Assembly instrument. They noticed that ubiquitous spots of extreme ultraviolet and X-ray light, known as brightpoints, prefer to hover around the vertices of these large areas, dubbed g-nodes.

"Imagine a bunch of helium balloons with weights on them," said Robert Leamon, co-author on the paper at Montana State University in Bozeman and NASA Headquarters in Washington. "The weights get carried along by the motions at the bottom. We can track the motion of the helium balloons floating up high and that tells us what's happening down below."

By opening up a way to peer inside the sun quickly, these techniques could provide a straightforward way to map the 's interior and perhaps even improve our ability to forecast changes in magnetic fields that can lead to solar eruptions.

Explore further: NASA's SDO sees giant January sunspots

add to favorites email to friend print save as pdf

Related Stories

NASA's SDO sees giant January sunspots

Jan 07, 2014

An enormous sunspot, labeled AR1944, slipped into view over the sun's left horizon late on Jan. 1, 2014. The sunspot steadily moved toward the right, along with the rotation of the sun, and now sits almost ...

SDO mission untangles motion inside the Sun

Aug 28, 2013

(Phys.org) —Using an instrument on NASA's Solar Dynamics Observatory, called the Helioseismic and Magnetic Imager, or HMI, scientists have overturned previous notions of how the sun's writhing insides move ...

Large coronal hole near the sun's north pole

Jul 20, 2013

The European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, captured this image of a gigantic coronal hole hovering over the sun's north pole on July 18, 2013, at 9:06 a.m. EDT. Coronal holes ...

Solar minimum; solar maximum

Nov 27, 2012

(Phys.org)—The picture on the left shows a calm sun from Oct. 2010. The right side, from Oct. 2012, shows a much more active and varied solar atmosphere as the sun moves closer to peak solar activity, a ...

Recommended for you

Cassini sees sunny seas on Titan

9 hours ago

(Phys.org) —As it soared past Saturn's large moon Titan recently, NASA's Cassini spacecraft caught a glimpse of bright sunlight reflecting off hydrocarbon seas.

Is space tourism safe or do civilians risk health effects?

12 hours ago

Several companies are developing spacecraft designed to take ordinary citizens, not astronauts, on short trips into space. "Space tourism" and short periods of weightlessness appear to be safe for most individuals ...

An unmanned rocket exploded. So what?

15 hours ago

Sputnik was launched more than 50 years ago. Since then we have seen missions launched to Mercury, Mars and to all the planets within the solar system. We have sent a dozen men to the moon and many more to ...

NASA image: Sunrise from the International Space Station

16 hours ago

NASA astronaut Reid Wiseman posted this image of a sunrise, captured from the International Space Station, to social media on Oct. 29, 2014. Wiseman wrote, "Not every day is easy. Yesterday was a tough one. ...

Copernicus operations secured until 2021

16 hours ago

In a landmark agreement for Europe's Copernicus programme, the European Commission and ESA have signed an Agreement of over €3 billion to manage and implement the Copernicus 'space component' between 2014 ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.