I built a nebula creation ship to try this trick but I couldn't get it to work. It always destroys the system my ship is in, not the other system that I want to destroy.
The problem is that as soon as I try to select a star in another system, my nebula ship is de-selected and now the stellar manipulation functions aren't available. I could view a different system while still having my ship selected, but then when I create the nebula, the local system is destroyed instead of my intended target.
I'm guessing that it doesn't work because I'm using turn-based mode. I'll have to start a new game in simultaneous mode and try it.
