Luke is fairly sure that Vader is navigating them through hyperspace. Which is impossible, but all things are possible, through the Force, and surely someone did it before they developed the technology to do it.

Normally, exiting hyperspace bring a flush of awareness, of real space and the Force within it, the scents and feelings of the nearby worlds washing over him.

All he feels now is Vader's presence.

"It looks beautiful from up here."