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.
False-color timelapse of NOAA active region 13567
Credit: IRIS, LMSAL/NASA, Roy Smart
Active regions (ARs) are temporary areas of enhanced activity on the solar surface, analogous to thunderstorms on Earth. They often contain one or more sunspots, and are a common source of solar flares and coronal mass ejections. ARs form when magnetic fields generated within the solar interior emerge into the overlying corona and force large-scale changes to the magnetic configuration of the solar atmosphere. In this timelapse, the human visible color spectrum has been shifted and compressed around an ultraviolet spectral line observed by IRIS, Si IV 139.4 nm. Viewing the spectral line in this way allows us to see subtle color changes, which are caused by supersonic flows in the solar atmosphere shifting the spectral line due to the Doppler effect. Over the course of this 2-week timelapse we can see two distinct phases of an AR lifetime: the emergence phase, characterized by intense activity and flows, and the decay phase, where the AR slowly fades away.