We Knew Solar Flares Were Hot, but This Hot?

Solar flares may be far more intense than scientists believed, with new research suggesting these fiery eruptions from the sun can reach staggering temperatures of 100 million degrees—possibly up to 180 million degrees. That's well over six times hotter than earlier estimates, according to research published Wednesday in Astrophysical Journal Letters. The "incredible" number comes from recent calculations and simulations that challenge the long-standing assumption that electrons and ions in solar flares reach similar temperatures, Alexander Russell, a study author and physicist at the University of St. Andrews, tells NPR.

Earlier predictions of solar flare temperatures were based on the temperature of electrons, per Smithsonian. Scientists figured ions were in the same ballpark. However, the latest computer models and data suggest ions heat up to dramatically higher temperatures than electrons. The implications go beyond academic interest. A better grasp of how solar flares heat up could help researchers develop improved models to predict these events, which can be hazardous to astronauts, satellites, and power grids on Earth. Russell's team is already working on the next phase of research: refining models to account for the extra-heated ions.