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.
Sparkling active region flux emergence
Credit: IRIS, LMSAL/NASA, Gregal Vissers (ISP/SU)
While waiting for big flares and eruptions, IRIS has gathered a wealth of active region observations that help us understand the various stages of their evolution in the (upper) chromosphere and transition region. This movie shows the well-developed active region NOAA AR12089 in the middle of June 2014, where the continuous emergence of magnetic fields into the lower solar atmosphere drives a host of compact brightenings popping up between the two sunspots. They mark locations where the magnetic fields reconfigure and energy is released as so-called UV bursts, sometimes extending into brightly arched micro-flares. Depending on the field configuration and evolution, these may set the stage for subsequent larger energy releases - as this active region indeed went on to do, producing several C-class flares in the following days.