‘What is it? ‘Scientists explain white spots that appear near aurora borealis’

The whitish-gray spots that sometimes appear in the night sky with the aurora borealis have been described for the first time by researchers at the University of Calgary.

The paper, published Dec. 30 in the journal Nature Communications, investigates the “structured continuous radiation” associated with auroras.

“You see this dynamic green aurora, you see some red aurora in the background, and then all of a sudden you see this structured, almost patch-like, grey-tone or white-tone emission connected together. “Even the aurora borealis,” said lead author of the study, Dr. Emma Spanswick, an associate professor in the School of Science’s Department of Physics and Astronomy.

“So a scientist’s first reaction is, ‘So what is it?'”

Spanswick said the white spots have been mentioned in scientific papers before, but never explained.

Her team’s paper concludes that it is “almost certainly a heat source” and says it suggests the aurora is more complex than previously thought.

Spanswick said the discovery was possible because advances in camera technology now allow amateur photographers and scientists alike to see true color images of the night sky.

“We’re all aware of the advances in digital photography. You can now take pictures of the Northern Lights with your mobile phone,” she says. “That is now flowing into the commercial sensor market.

“These types of sensors are now being incorporated into more commercial and more robust sensors used in scientific fields.”

The team’s research comes after the discovery and observation of a long, glowing purple ribbon of light known as STEVE (Strong Thermal Radiation Velocity Enhancement) sparked renewed interest in continuum radiation.

“There are parallels between what we’re seeing now and Steve,” Spanswick explains. “STEVE appears as this mauve or gray-toned structure.

“To be honest, the altitudes of both spectra are very similar, but due to their association with dynamic auroras, this is almost embedded within the aurora, even though it is difficult to tell them apart in person. STEVE, on the other hand, is something else: a large band across the sky.”

This latest study is also significant in that it includes three University of Calgary students, including undergraduate Josh Houghton, who was initially hired as an intern for the project.

“I was still learning at the time,” he says. “I just started my internship and was able to jump right in. It’s very, very nice.”

Spanswick said Horton did a lot of the analysis of the research, which led him to contribute to the Nature paper as an undergraduate.

“He had a great experience with his internship,” she says.

Houghton plans to continue her research as part of her undergraduate honors thesis before completing her master’s degree at the University of Calgary next year.