Star Key is in Angela's Bar on Vedan. Trick is, the bar is closed for a couple chapters after you finish your first visit to Vedan, so if you missed it, you have to wait.
Sun Key.... I think it's in Johannasburg on Rosa, which might be a place you haven't reached yet, since I don't know how far you are. I forget where in that place the key is, but I know that it is in a chest locked by the Star Key, so first things first.
"As the good archmage often admonishes me, I ought not to let my mind wander, as it's too small to go off by itself." -Danilo Thann