Astronomers watch huge solar eruption 10 times more powerful than ever seen on the sun

A sun-like star across the Milky Way gives scientists a window into the past.

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Jackson Ryan was CNET's science editor, and a multiple award-winning one at that. Earlier, he'd been a scientist, but he realized he wasn't very happy sitting at a lab bench all day. Science writing, he realized, was the best job in the world -- it let him tell stories about space, the planet, climate change and the people working at the frontiers of human knowledge. He also owns a lot of ugly Christmas sweaters.
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An artist's impression of a superflare at the star AD Leonis. The telescope that captured this flare also helped to analyze EK Draconis in the new study.

National Astronomical Observatory of Japan

Using NASA's powerful planet-hunting space telescope, astronomers have spotted a monstrous solar eruption, more powerful than any previously seen in our solar system. Fortunately for us, the red-hot flare ripped through space some 111 light-years from Earth, erupting from a star known as EK Draconis (or EK Dra).

The star resembles a younger version of our own sun and could provide a window into our own solar system's past. 

"Planetary atmospheres, or habitable environments, are being established around young stars," said Kosuke Namekata, a sun scientist at Kyoto University in Japan and first author on the paper. "Our research can contribute to the understanding of the environment in which life is born." 

The discovery, published on Dec. 9 in the journal Nature Astronomy, was made by Namekata and colleagues using NASA's Transiting Exoplanet Survey Satellite, or TESS, which observes distant stars in search of planets. But the team wasn't hunting other worlds, it was looking for solar flares. Stars, like our sun, are vibrant and violent places that can spew out sudden explosions of radiation known as coronal mass ejections after a flaring event. These outbursts cause radiation to spill out to space, and they can even reach the Earth, where they interfere with satellites in orbit.

While viewing EK Draconis on April 5, 2020, the team spotted a superflare event. This isn't unusual for a star, but as they continued to observe the outburst, they spotted what could be a coronal mass ejection. And it was an extremely powerful one.

"What we observed was an eruption that was more than 10 times more massive than the largest CME ever observed on the sun," said Namekata. 

NASA filament eruption Sol

A filament extends from the sun, which is being blocked by the telescope so it can view the environment surrounding the star.


Namekata says the team observed a filament eruption, which is kind of like the first stage of a mass ejection, but it's uncertain whether this is a fully fledged CME. However, comparing the data with data from our sun, he noted that "it is almost certain" to be the latter.

Does that mean we might see a massive flare and ejection from our home star? There are a few key differences between EK Dra and the furnace at the center of our solar system. Age is the biggest factor, with our sun some 4.5 billion years older than EK Dra. Younger stars are much more likely to release huge flares than the middle-aged heater we see in the sky each day -- but that doesn't mean we're out of the woods yet.

"According to our previous research, it is possible that such a phenomenon could occur in our current sun," says Namekata, noting one huge caveat. "The frequency of the occurrence is low." He suggests such an event would likely only occur "once every few hundred years." Phew.

However, back when the sun was just a fledgling inferno it may have been throwing out the same superflares as EK Dra -- and that would have implications during the formation of planets like Earth and Mars. How did the flares and ejections affect these planets, and how did they affect the star itself? We can't quite say just yet, but Namekata is working on a project that will capture more flares and eruptions, noting that "the frequency of these eruptions is quite important" in understanding the evolution of the early solar system.