Soldato
Vadar arrives in a new Destroyer I think. Remember the Death Star just arrived and the Rebel fleet literally jumps to hyper space but is blocked, literally by a new Destroyer jumping out of Hyper Space.
If you watch it again the star destroyer doesn't dock. Vadar gets the report the Rebel command ship has been disabled so Vadar takes a Imperial Shuttle (one where we are all familar with- inverted Y) and travels to it escorted by a couple of Tie fighters.
I presume he then docks onto the Rebel Ship with a few soldiers.
Am I right to think that the ship escaping happens immediately in Episode 4 or is there some time for it to travel to somewhere before Vadar catches up again??
I would say a bit of time since he would have to find the right CR90. Otherwise the 'diplomatic mission' spiel of Ep IV would not make any sense.