From the description of the sheets and the pulsations it could be some form of aurora. I've seen faint sheets that have been directly overhead or apear to emanate from a crown. Colours are usually a milk in water bluish white though I have seen faint red ones as well. If you are an accustomed skywatcher though I would assume you know what an aurora looks like and normally with an overhead crown there's a lot of really colourful activity elsewhere. Last night activity was pretty quiet but it is
starting to pick up.
If I may ask Minbari, what is your location/latitude?