TEC starbase has a build ships ability. So they'd have to include that with all stars/planets. Although the TEC starbase can only build frigates and cruisers...
i dont usually use that ability on starbases, but from my understanding last time i used it, if you want to build ships from the TEC starbase, then you need to click on the starbase itself, not the planet...
regardless, these were GW's with no starbase, either plasma clouds etc, or soverign, allied or enemy planets... im pretty sure it shouldnt be happening