IRIS Movie of the Day
At least once a week a movie of the Sun taken by NASA's Interface Region Imaging Spectrograph (IRIS) is posted by one of the scientists operating the instrument.
Flare and failed eruption.
Credit: IRIS, LMSAL/NASA, Magnus Woods
Solar flares are often associated with filament eruptions. Filaments consist of relatively cool plasma that is supported against the Sun's gravity by magnetic forces. Filament eruptions occur when the magnetic field becomes unstable which results in plasma being ejected outwards through the solar atmosphere. These ejections can also result in flares. Sometimes these erupting filaments escape the Sun's atmosphere and become coronal mass ejections, traveling into interplanetary space. However, sometimes the magnetic conditions in the solar atmosphere result in the eruption being unable to continue out of the atmosphere. The plasma that made up the eruption then falls back into the Sun. In this movie we see a C-class solar flare in progress. This C-flare accompanied a failed filament eruption. We can see lots of plasma flowing along magnetic field lines back toward the solar surface, after being unable to erupt fully.