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.
Coronal loops trace the bipolar magnetic field
Credit: IRIS, LMSAL/NASA, Sean Brannon
Did you ever do that experiment in school where you use a container of iron filings and bar magnetic to visualize a magnetic field? If not, this IRIS observation of Active Region 12852, taken on August 6 2021, provides a pretty good substitute. Active regions on the Sun occurs when the solar magnetic field breaks through the Sun's surface. In this case, the IRIS spectrograph slit (the dark line running vertically down the center) happens to be placed right between the magnetic north and south "poles" of this active region. The solar coronal plasma is trapped on the resulting magnetic field lines, similar to the iron fillings are in the school experiment. The arcing loops that result beautifully demonstrate the prototypical bipolar North-South field.