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.
A Precarious Prominence
Credit: IRIS, LMSAL/NASA, Chad Madsen, SAO
In this movie, we see a prominence on the eastern limb of the Sun with some odd structural quirks. A prominence is an arch of relatively cool plasma dredged up from the lower solar atmosphere and suspended high above the solar limb by magnetic forces. Here, we're looking at one leg of the prominence arch, or more specifically the UV radiation emanating from ionized gaseous magnesium (Mg) in one leg of the arch. Near the center of the frame, we see what appears to be two pieces of the arch leg pushing against each other horizontally. Then a flow of material seems to squeeze out of this area downward and fall back toward the solar surface. It's unclear what exactly is happening here physically, but we can say that this is a very complex structure, and complexity usually begets instability. So, don't pin your hopes on this prominence sticking around much longer!