Solar-resembling Stars Frequently Erupt with "Superflares" Every Century, Research Indicates
Recently, our planet encountered two geomagnetic disturbances, triggered by solar radiation bursts from the Sun. These storms impacted satellites in orbit and terrestrial communication networks. Research suggests that the Sun might be capable of generating far more potent solar flares than we've previously witnessed.
Scientists have been scrutinizing the Sun for roughly six decades now, while simultaneously analyzing stars that share its properties to predict future behavior. With this approach, they hoped to uncover whether the Sun could yield superflares, which are many times more powerful than ordinary solar flares. By scrutinizing data from 56,000 Sun-like stars, they identified approximately 2,889 instances of superflares on 2,527 of these stars, suggesting that superflares occur roughly once per century in stars similar to the Sun.
Although the Sun hasn't demonstrated any superflare activity to date, historical solar events leave traces of isotope spikes on Earth. However, these events do not match the energy levels expected from a superflare, according to research data. Nonetheless, findings published in the journal Science could offer insights into the Sun and potentially help predict future geomagnetic disturbances impacting our planet's technology.
Valeriy Vasilyev, from the Max Planck Institute for Solar System Research, and principal author of the study, tells Gizmodo, "Our chief goal was to ascertain how frequently the Sun produces superflares, but our duration of direct solar observations is comparatively brief."
Instead of relying on Solar observations, the researchers analyzed data collected by NASA's Kepler space telescope, which searched for exoplanets during its nine-year mission. "An alternative method is to analyze the vast data accumulated by space telescopes, such as Kepler, by monitoring approximately 56,000 Sun-like stars over a span of four years. This amounts to around 220,000 years' worth of solar observations in sum," Vasilyev explained.
The research also revealed that the frequency of superflares aligns with traditional solar flare patterns from the Sun, implying a shared underlying mechanism. A regular solar flare emits the energy equivalent of about ten million times a major volcanic eruption on Earth. Superflares, by contrast, are 10,000 times more powerful than solar flares.
Solar flares represent a natural phenomenon associated with solar activity. The Sun adheres to an 11-year cycle that influences its activity level. At present, the Sun is undergoing its solar maximum phase, a period characterized by heightened solar flare activity and coronal mass ejections. A significant geomagnetic storm, categorized as G5 or extreme, struck Earth in May due to large plasma release from the Sun's corona. This was the first G5 storm to hit Earth in more than two decades, bringing about harmful effects on the power grid and causing a shift in satellite positions in low Earth orbit.
"If accompanied by a coronal mass ejection (CME), a superflare could lead to extreme geomagnetic storms on Earth, which may disrupt technological systems," Vasilyev said.
Detailed investigations are required to ascertain whether the observed stars vary from the Sun or if their activity hints at our host star's future potential, Vasilyev noted. The Sun is categorized as a typical yellow dwarf star. Nevertheless, recent discoveries suggest that it exhibits lower brightness variability compared to most Sun-like stars in the Kepler telescope's field of view, according to Vasilyev. This implies that the Sun is less active than most solar analogs, he added.
The study accounted for this aspect by incorporating a larger and more representative sample of Sun-like stars, yet it remains unclear if this would impact the Sun's ability to generate superflares like its solar counterparts.
The study of space and solar activity has led scientists to consider the future potential of the Sun, as they've identified superflares occurring approximately once per century in stars similar to our Sun. advanced technology, such as NASA's Kepler space telescope, can provide valuable data to help predict future geomagnetic disturbances caused by superflares, which are significantly more powerful than regular solar flares, and could result in extreme geomagnetic storms that disrupt technological systems if accompanied by a coronal mass ejection.
