Thank you for reminding me that you don't always have all the systems as explored.
I must be spoiled by two team games where the Ancient trait is in and a few other games where I did know the whole galaxy.
Incidentally, I would have another query about Stellar Manipulation: is it possible to give Stellar Manipulation orders to a ship, then put it in a fleet and order it to move away? Would the order to, say, Close a Warp Point, be kept after this? It should work, but I would rather be sure about this as... Well, I have wasted enough turns and resources on these Stellar Manipulation ships to afford yet another delay with another fleet going on against my worlds.