Mark Johnston from Scottsdale, Arizona
On Aug. 21, 2026, an unusually long-lasting M-class flare erupted from a sunspot group near the Sun’s west limb. As the flare’s stretched magnetic field lines reconnected and relaxed, they filled with hot plasma that cooled and drained along the loops, producing the glowing arcade seen here in Hydrogen-alpha (Hα) light. The imager used a 6.3-inch f/7 refractor with a 4x amplifier feeding a 0.3-angstrom Hα etalon filter, stacking and processing high-speed video captured over 2 hours and 16 minutes into a time-lapse compressed to about 35 seconds.