I was trying out the live composite mode of my Olympus camera, until 1AM!
Last night was a clear night so these photos were taken looking north from my bedroom.
A straight shot, F2.0, ISO 200, 25mm lens, 2 seconds:
An 18 minute exposure using live composite, F2.0, ISO 200, 25mm lens:
Looking at the second image, I could see a few dust spots, quickly removed in post.
Looks cloudy tonight, so can't try again.