Project Galaxy
The largest space station ever created. Project Galaxy was a superweapon thought up in 3800. By the year 3805 work on the structure had begun. The project was completed in 3819. Further improvements prevented its deployment until 3820. The station's central disk has a diameter of 550 AU and the outer ring's diameter is 1200AU. The enormity of the two stations means that their arrival spells doom to any one that comes between them. Additionally they can be used separately though the primary weapon will be less effective.
The Primary weapon fires two weapons at once. At the center, a 5 AU wide beam of high energy molten metal is fired at .8c streaming towards a center point where both beams, one from each station, meet. Right outside of that zone is the rest of the primary firing mechanism, with a diameter of 100 AU an beam of energy destroying everything in its path.