Megakelvin campfires on the Sun

Abstract

Solar Physics\nThe Sun s corona (diffuse upper atmosphere) has a temperature of several million kelvin, far hotter than the photosphere (visible surface). The origin of the required coronal heating is unknown, with numerous proposals under investigation. Berghmans et al. observed the Sun in extreme ultraviolet light using the Solar Orbiter spacecraft. They identified hundreds of small, bright flashes near the base of the corona, which they call “campfires.” These campfires lasted 10 to 200 seconds and reached one million kelvin. Similar features have previously been seen above active regions, but the authors show in this study that they also occur on the quiet Sun in sufficient numbers to plausibly provide the coronal heating. The driving mechanism remains unknown.\n\nAstron. Astrophys. 10.1051/0004-6361/202140380 (2021).