I really did not know but my experience and gut feeling was low ISO and longer exposure. I suppose that came from years ago being with my dad when he tried these shots.   Glad to see that confirmed by folks who know.  Thanks...TomDart.

Yes, the stars and heavenly objects move(we move) much faster than expected. As earth turns from west toward east, the stars appear to be going west.  On the north star, the movement is circular.  Turning east is only to greet the morning sun!  I like that part.