[Q]

Originally posted by QuarianRex:
Unfortunately you cannot creat a star in a system that contains a constructed planet. The sphere/ringworld counts as a star and a planet for the purposes of stellar manipulation but is unaffected by stellar manipulations that target either (ie. it can't be blown up when targeted by tectonic bombs, star destroyers, black hole creators, etc., though such things can affect other stars in the system with disasterous results).

Edit: D'oh! Missed it by that much.

You can blow up a sphere- or ringworld with a tectonic bomb, but you have to mod the targeted planet level to a higher value.