I've already posted this, but I think it may be useful as an "idea":


A gas giant (or any other planet) cannot turn around... nothing.


There has to be some (huge) mass at the center of the system to keep it on its orbit, otherwise it will go in a "straight" line (just like two ice skaters turning around each other, if you remove one of them, the other one is ejected). I have put "straight" in quotes because nothing is really straight in space, if there is no star in the system the gas giant will in fact orbit the center of the galaxy.


So here are some suggestions:


- Nothing is visible at the center of the system, so we can pretend the gas giant is orbiting a black hole (that's my current "default" interpretation)

- You could add a star in these systems or

- You could remove the orbit of the gas giant (it replaces the star, it's an aborted star) or

- You could add some unknown alien technology (maybe with some lore) that produces an invisible huge mass at the center of the system


A simple fix may be to at least not draw the orbit.