Solar eruptions aren't slinky-shaped, study finds

Aug. 30 (UPI) -- New analysis of old data has undermined common assumptions about the shape of the sun's coronal mass ejections.

Coronal mass ejects, or CMEs, are large eruptions of plasma and high energy particles from the sun's atmosphere. They trigger powerful solar storms, which can disrupt power grids and satellite communication systems if they strike Earth.

An improved understanding of CME structures could help scientists more accurately predict space weather and protect satellites.

"Since the late 1970s, coronal mass ejections have been assumed to resemble a large slinky -- one of those spring toys -- with both ends anchored at the sun, even when they reach Earth about one to three days after they erupt," Noe Lugaz, research associate professor at the University of New Hampshire's Space Science Center, said in a news release. "But our research suggests their shapes are possibly different."

Current measurements of CMEs are limited, allowing for only a 30-to-60 minute warning before CME-triggered storms hit Earth. Scientists want to extend the warning period to two hours, and eventually a full 24 hours.

To better characterize the shape and structure of CMEs, scientists returned to a dataset collected by NASA's CME-probing satellite duo, Wind and ACE. Normally, Wind and ACE are side by side, offering scientists a single point reference. But between 2000 and 2002, the two satellites were separated.

The dataset offered scientists a unique opportunity to gain a two-point perspective.

"Because they are usually so close to one another, very few people compare the data from both Wind and ACE," said Lugaz. "But 15 years ago, they were apart and in the right place for us to go back and notice the difference in measurements, and the differences became larger with increasing separations, making us question the slinky shape."

New analysis of the old data suggests CMEs are not shaped like big, simple slinkies. The ejections are either significantly deformed slinkies, scaled-down slinkies or another shape entirely.

Scientists hope future multipoint observations of CMEs will help astronomers more accurately characterize the formation of coronal mass ejections and improve space weather prediction models.

Researchers detailed their analysis this week in Astrophysical Journal Letters.