In Nebulb each processing performed is stored in a self-contained project file (files with extension *.nbp), in which Nebulb saves all the information generated during the stacking and, also, all the processing adjustments applied by the user.
That is, the project files contain all the necessary information to be able to apply all the desired adjustments on the image resulting from the stacking (without the need to have the original image files).
Obviously, due to a data volume issue, the project files cannot contain all the original images imported into Nebulb (they only contain the original base image and the references to the rest of the images), but once the stacking is done Nebulb does not need to have the original images (everything it needs is in the project file).
In addition, all the adjustments made in Nebulb are non-destructive, so you can make all the modifications you want without degrading the image.
ATTENTION: In case you want to execute the stacking again or refine it (because you have selected another time of the night to align the flying objects), then Nebulb will need again the files of all the original images imported in Nebulb.
Within the "File" option of the main menu you can find all the options to manage Nebulb projects.