A star over 100 light-years away in the constellation Draco is teaching us a few unsettling things about our own Sun. The star, EK Draconis, recently surprised researchers when it launched into an explosive light show more energetic than anything observed from our local star. If our Sun erupted in the same way, it would be seriously bad news for our electrical grids and satellites.
EK Draconis is about the same mass of the Sun but is much younger, at about 100 million years old (compared to the Sun’s 4.6-billion-year life.) As stars, both objects are made of superheated gas. Sometimes, plasma can fall back to the solar surface and light up in what’s called a solar flare. Those flares can be small, like the little ‘campfires’ on our Sun that were first observed by NASA’s Solar Orbiter last year, but sometimes these arcs of energy can be much larger.
Superheated material can be ejected out into space in what’s called a coronal mass ejection. A team of researchers studying EK Draconis recently saw the star spew plasma in an explosion 10 times larger than any previously observed from a Sun-like star. Their results were published today in Nature Astronomy.
“The results help us to improve understanding on how coronal large mass ejections have occurred over the 4.6-billion-year history of Sun-sized stars and our Sun itself,” said study co-author Yuta Notsu, an astrophysicist at UC Boulder and the National Solar Observatory, in an email to Gizmodo. “Although such big super CMEs occurred much more frequently at a younger age, this event can be a proxy for the possible super CMEs associated with possible superflares once every hundred or thousand years on our current Sun.”
So perhaps one day our Sun could spout off a similarly large coronal mass ejection. Even the milder solar flares we experience are already impositions enough; when directed at Earth, the phenomena can mess with electronics and the orbits of satellites. A coronal mass ejection of significant size would completely fry those satellites and knock out entire electrical grids.
Notsu’s team observed EK Draconis for 32 nights in 2020 using NASA’s TESS satellite, which typically searches for new exoplanets, and Kyoto University’s SEMEI Telescope in Japan. One night in April, they saw the spectacular: The star let loose a huge flare, followed up about a half hour later by the first stages of a coronal mass ejection. That stage—called a filament eruption—saw plasma shoot off the star at about 1 million miles per hour.
Notsu said that, so far, the team has only observed that initial phase of a coronal mass ejection; to see later stages, they’d need to look at EK Draconis in different wavelengths using ultraviolet and X-ray telescopes. “Moreover,” Notsu added, “we also would like to collaborate more with planetary scientists for more detailed discussions on super CME effects on the young solar system.”
When our Sun gets older—much older—its behavior will become more extreme, with the star eventually billowing outwards and then rapidly condensing into a white dwarf. By that time, humans (or perhaps more accurately, whatever humans evolve into) will probably not be around. But if we were, we’d be burned to a crisp, so perhaps it’s best to be grateful for the Sun as it exists today and cross our fingers we avoid any EK Draconis-like superflares.