Eruptive events on the sun can come just with a solar flare; some come with an additional ejection of solar material called a coronal mass ejection (CME), and some with complex moving structures in association with changes in magnetic field lines that loop up into the sun's atmosphere, the corona. This eruption occurred on the sun that produced all three: a moderately powerful solar flare exploded on the sun's lower right limb, sending out light and radiation, nextcame a CME, which shot off to the right out into space, and then, a phenomenon known as coronal rain.
Hot plasma in the corona cooled and condensed along strong magnetic fields in the region. Magnetic fields, are invisible, but the charged plasma is forced to move along the lines, showing up brightly in the extreme ultraviolet wavelength of 304 Angstroms, which highlights material at a temperature of about 50,000 Kelvin. This plasma acts as a tracer, helping scientists watch the dance of magnetic fields on the sun, outlining the fields as it slowly falls back to the solar surface.
Source: courtesy of NASA’s Solar Dynamics Observatory's Atmospheric Imaging Assembly (AIA) instrument.
