Danger factor
From Starsonata Wiki
Danger Factor is a numeric value assigned to a galaxy based on its distance from the closest AI protected galaxy. Each jump from the closest AI protected galaxy adds 10 to the Danger Factor, where AI protected galaxies start with a Danger Factor of 10. This is used to determine several things, including the level of Warp Navigation required to enter, difficulty of AI, the ability to build bases, and PvP attack range.