ShadowZero (Yeah, but you didn't word it well. Instead of "the system seemed completely empty because the fighter did not detect any sign of energy in the system", making it sound like there was a specific system you entered into and assumed that it was empty, try something like "They entered this system due to the lack of energy" or something similar, so instead of sounding like you picked the system, then assumed it was empty, it sounds the other way around where you picked the system because it didn't have any energy.
As predicted, there are no man-made structures in the system. Normally, all edge systems have guard posts, since vassal states are required to have guard posts along their borders- however, the laws are far more lax in the core empire itself, so the northern border which is the only area where princes are exposed to unclaimed space, so there are a couple of holes in the north.
The system itself is unassuming- a small red dwarf star and a couple of rocky planets around it.