Dark skys

I wonder why I've not tried this before.... star trails. I've shot the ISS but no trails.
This first attempt is one exposure of 5 minutes or so. They tell me I may find "noise" or color dots with very long exposures. So far I can't find any. If I do there is a method to expose two shots, one with the lens cover on and combine it with the "real" image. Or just take multiple shots and combine them...... maybe next time. The arrow "less than" points to Polaris. edit: I forgot to mention "best large".