A solar flare is a sudden flash of brightness observed over the Sun’s surface or the solar limb, which is interpreted as a large energy release. The sun emitted a mid-level solar flare, peaking at 11:50 p.m. EST on Dec. 16, 2014. NASA’s Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event.
Flares occur when accelerated charged particles, mainly electrons, interact with the plasma medium. For more questions about solar flares and their observations check out the Spaceweather Frequently Asked Questions page from NASA.