This image from NASA's IRIS spacecraft shows the region around two sunspots - the dark areas at upper left and lower right. It shows emission from ionized silicon (Si IV) in the transition region at a temperature of about 116,000 degrees Fahrenheit, plus ultraviolet
continuum from the chromosphere at a temperature of about 17,000 degrees F. The bright dots are short-lived, intense patches of Si IV emission. The role that these dynamic events have in heating the solar atmosphere is currently unknown.