S Flare

Left: A sigmoid before an eruption. 8 June 1998 15:19 UT. Solar X-ray image from the Yohkoh Soft X-Ray Telescope.
Right: A sigmoid with a cusp, indicating an eruption has taken place. 9 June 1998 16:17 UT. Solar X-ray image from the Yohkoh Soft X-Ray Telescope