I've got one better. Planets orbit their star. What if the aliens have antigravity devices so a planetary-mass object doesn't orbit its star or some other plane

I've got one better. Planets orbit their star. What if the aliens have antigravity devices so a planetary-mass object doesn't orbit its star or some other planet. Then what will we call it? ("That's Not A Moon...It's A Space Station!" tells us that those people long ago and far away didn't think that moon had to orbit a planet.) To add more fun to the pile, is the "rogue planet" PSO J318.5-22 a planet? https://en.wikipedia.org/wiki/PSO_J318.5-22 https://en.wikipedia.org/wiki/PSO_J318.5-22 . And yes, the IAU has already considered this case.