The only way to obtain a ‘true’ 4 minute shot without a star trail is by using an Astro Tracer.
The Pixel 4 takes an exposure only lasting for 15 seconds, even if you shot a full four-minute shot. Google essentially stacks and processes 16 15-second exposures.
Another reason you don’t take lengthy shots is with items such as the surface of the Moon. The Pixel is unable to capture the moon’s details and a moonlit landscape in the same image.
However, a decent 15 second shot taken with the iPhone can produce spectacular results.
See this thread for examples:-
https://forums.macrumors.com/thread...w-i-cant-believe-this-is-a-phone-pic.2202319/