aeksora

Hi all, I am pretty new to Astrophotography and I recently wanted to stack multiple nights of data in Sirilic. It went pretty well, but the stacking took almost 4 hours because of the amount of images. If I wanted to add another night of data, can I just take the file that came out when I stacked previously and use it as a light without any calibration frames or do I have to use all lights from the previous sessions again? Using just one file for the previous sessions would significantly reduce the time I have to wait for it to stack. Thanks in advance!