I plotted some data of the speed of Voyager 2 for various times (around the Jupiter flyby) and noticed that the highest speed that Voyager achieved was not at perijove and was wondering why this might be the case.
I found online that Voyager 2 made its closest approach to Jupiter at 22:29 on July 9th, 1979 (which should also be the point at which its velocity is highest. I then plotted some of the velocity data from JPL and noticed that its highest velocity was actually around 8 hours later. I was wondering why this might be the case? Could it simply be an error in the measurement or is this difference really insignificant for it to matter? I was just curious since I found it strange that the data doesn't match.