"What," you ask, "is a wormgate doing light-years from an inhabited system?"
The answer is simple. It's in transit. The gatekeepers are expanding their network in this region, and the wormgate was flying by as this picture of the Serial Peacemaker was snapped (err... drawn. Whatever). That glow in the middle is NOT a starfield... it's the wormgate mechanism being used to feed hydrogen into a magnetic bottle, where it is then fused, charge-coupled, and ejected as part of a crude plasma drive.
"Why," you ask, "is something with the mass of Uranus being flown with ancient plasma drive technology?"
We refuse to answer that question. You just asked it so you could use the phrase "mass of Uranus." Admit it.