Proceedings of the Polish Astronomical Society: We have analysed a long-lived coronal cavity observed from 17 March 2012 to 21 March 2012. For this cavity we applied a differential emission measure method to obtain both a temperature distribution and the average temperature over all five observational days. We find that the cavity is filled with material hotter than its surroundings. The temperature remains stable during all five days.
Average temperature map (log T) for a cavity observed on 2012 March 17, 18, and 19, determined via Differential Emission Measure (DEM) from Solar Dynamics Observatory/Atmospheric Imaging Assembly observations.