EK Draconis illuminates an unimagined picture of how superflares may affect interplanetary space through coronal mass ejections
By Yuta Notsu, Astrophysicist, NSO and CU Boulder Researcher
Welcome to the New Year! While Earth celebrated 2022’s arrival with displays of fireworks, the greatest “fireworks show” in our solar system often occurs on the Sun. Its atmosphere is a venue for dynamic sunspots, solar flares, and dramatic encores of released magnetic tension casting plasma particles into the cosmos via coronal mass ejections (CME).
We’ve seen and studied CMEs from our own Sun, and often use these observations to guide our understanding of the broader universe by extrapolating these findings to other stars.
However, actually seeing these distant observations is difficult – but our team did just that.
In 2020, I worked as part of a research team led by Dr. Kosuke Namekata, National Astronomical Observatory of Japan, that successfully witnessed a massive CME taking place on a distant star. On April 5, 2020, we observed the beginning of a CME forming on EK Draconis. At roughly 50-125 million years in age and 111 light-years from Earth, EK Draconis is a young, solar-type star similar to our Sun, making it a prime candidate to make such extrapolations. It’s what our Sun would have looked like 4.5 billion years ago.
Using NASA’s Transiting Exoplanet Survey Satellite (TESS) and ground-based telescopes including Kyoto University’s SEIMEI Telescope, we captured the “first” evidence of a filament eruption – the early phase of a CME associated with a powerful superflare relative to the star’s size and age. This rare observation suggests that a strong CME, 10 times larger in mass than the largest recorded solar CME, can occur from a superflare on a young, Sun-like star.