A Maunakea telescope observing distant stars detected a stellar flare estimated to be 10 billion times more powerful than any solar flare from our sun.
The James Clerk Maxwell Telescope observed a powerful stellar flare — a burst of plasma and electromagnetic radiation — in November 2016 from a star 1,500 light-years from Earth, but the data was not found and analyzed until August of last year.
Solar flares are a not unusual phenomenon that are sporadically observed on our own sun.
“The average solar flares on our sun are pretty dramatic,” said astronomer Steve Mairs, lead investigator of the team that discovered the flare. “There are stories of telephone lines exploding because of flares in the past.”
However, Mairs said that because the 2016 stellar flare was detectable from so far away, the flare is thought to be unimaginably more powerful — releasing 10 billion times more energy — than any flare from our solar system’s star.
The discovery of the flare could lead to a better understanding about the process of stellar formation, Mairs said.
The flare emanated from a point in the Orion Nebula, which is the closest region of massive star formation to Earth, Mairs said. From this, Mairs said the source of the flare was likely a very young star in the process of forming.
Although the flare was discovered in 2016, it actually occurred approximately 1,500 years ago, with the light from the flare only reaching Earth three years ago. Despite this, Mairs said the star is still very young, cosmically speaking, as stars take more than 10 million years to fully form.
Mairs said the cause of the flare is speculated to be a powerful magnetic field funneling matter into the growing star. As the star formed, the magnetic field became distorted and briefly “snapped” and reconnected, releasing an extraordinary amount of energy.
Mairs said similar “snaps” have been observed in the past, but none at the scale of energy observed from the 2016 flare. The James Clerk Maxwell Telescope observes electromagnetic wavelengths of less than a millimeter; similar events in the past occurred at longer wavelengths, indicating less energy involved.
“One of the questions we have about star formation is ‘how do stars get all that mass?’” Mairs said. “Is it like a smooth process like a buffet, where you just get more and more matter as time goes by? Or does it happen in spurts, where you get a lot of mass at once and then nothing happens for a while, like a 12-course meal?”
The 2016 flare suggests star formation is more like a 12-course meal, Mairs said, and similar events might occur when stars “feast” on new matter.
The star that discharged the flare is thought to eventually become a star not too dissimilar from our own sun, Mairs said, aside from the fact that it exists in a binary system, revolving in tandem around a second star. However, Mairs assured that our star, a fully-developed star at roughly the center of its lifespan, is unlikely to produce a flare of any magnitude close to the 2016 flare.
Further investigation into similar events will hopefully lend further insights into star formation, Mairs said.
“We want to figure out how often this happens,” Mairs said. “We weren’t really looking for this one, we were just looking in the right direction.”
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