'Brightpoints' May Be a New Clue to Predicting the Sun's 11-Year Solar Cycle

About once every 11 years, our sun reaches the peak of its solar cycle. It turns from relatively quiet and calm to violently active as it approaches its solar maximum. Yet determining exactly when this maximum occurs is difficult; now, scientists may have discovered a new marker to track the course of the solar cycle--brightpoints.

"Sunspots have been the perennial marker for understanding the mechanisms that rule the sun's interior," said Scott McIntosh, first author of the new paper, in a news release. "But the processes that make sunspots are not well understood, and far less, those that govern their migration and what drives their movement. Now we can see there are bright points in the solar atmosphere, which act like buoys anchored to what's going on much deeper down. They help us develop a different picture of the interior of the sun."

Brightpoints are little bright spots in the solar atmosphere that allow astronomers to see the constant roiling of material inside the sun. The markers actually provide a new way to watch the way the magnetic fields evolved and move through the sun.

Over the course of the solar cycle, sunspots tend to migrate progressively lower in latitude toward the equator. The prevailing theory is that two symmetrical grand loops of material in each solar hemisphere sweep from the poles to the equator where they sink deeper down into the sun and then make their way back toward the poles. The theory suggests that sunspots move in sync to this flow. Yet scientists have long wondered why sunspots didn't seem to follow this pattern. That's why they started tracking the size of different magnetically balanced areas on the sun. In the end, the researchers noticed spots of extreme ultraviolet and X-ray light, known as brightpoints, prefer to hover around the vertices of these large areas, dubbed "g-nodes," because of their giant scale. These brightpoints in particular show scientists a bit more about what's happening in the sun's interior.

"Above that latitude, the solar atmosphere appears to be disconnected from the rotation beneath it," said McIntosh. "So there is reason to believe that, inside the sun, there's a very different internal motion and evolution at high latitudes compared to the region near the equator. 55-degrees seems to be a critical latitude for the sun and something we need to explore further."

The findings are published in The Astrophysical Journal.