New technique could help probe Sun's depth

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," Scott McIntosh, first author of the research said.

"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," he said.

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.

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.

The research is published in The Astrophysical Journal Letters.