(PhysOrg.com) -- Behemoth sunspot 1302 unleashed another strong flare on Saturday morning--an X1.9-category blast at 5:40 am EDT. NASA's Solar Dynamics Observatory (SDO) recorded the extreme ultraviolet flash.
The movie (below) also shows a shadowy shock wave racing away from the blast site. This is a sign that the blast produced a coronal mass ejection (CME) that could deliver a glancing blow to Earth's magnetic field on Sept. 26.
Since the X1.9-flare, active region (AR) 1302 has unleashed M8.6 and M7.4 flares on Sept. 24 and an M8.8 flare early on Sept. 25. None of the blasts have been squarely Earth-directed, but this could change as the sunspot turns toward our planet in the days ahead. AR1302 is growing and shows no immediate signs of quieting down.
Explore further: Sunspot 1283 bristling with flares: An X1.8 and an M6.7