system
Given the following post, respond as if you're commenting on Reddit:
human
[W40k] What is the standard Imperium procedure after finding a lost colony?

Let's say, for example, someone finds a world that has been forgotten about. Not a big deal, the Imperium finds and loses planets daily due to the sheer scale of it. The populace wish to rejoin the Imperium and all's good right? 

But what happens next? How do they decide who becomes the Governor? Will it be given to one of the locals or some Terran noble? 

How much interference will the Imperium have on this new planet? Will they just collect their tithes and ultimately leave them alone with no military presence?
gpt
The Governor is put in place from the populace, or assigned by the Imperium (I think the latter is SOP), and then the planet is surveyed to determine the worth of its tithe, and then the Governor is expected to get that tithe to the Imperium by the deadline.

Governor is definitely not a Terran Noble, since they really love being *Terran* nobles.

Most colonies are left to their own as long as they don't go to Chaos, leave the Imperium, and give their tithes.